Twenty
Salesforce's core workflow, open-source and on your own server: Twenty is a modern CRM built as exactly that alternative. It ships the standard CRM objects out of the box: people, companies, opportunities, notes, and tasks, displayed in table and kanban views with drag-and-drop and real-time updates. Its defining technical feature is a metadata-driven data model: you define custom objects and fields in the UI, and the backend regenerates its GraphQL schema at runtime, so a new object gets working queries, mutations, filters, and sorting within seconds, with no migrations to run - adapting the CRM to your sales process never requires code changes. A REST API is auto-generated from the same schema, GraphQL subscriptions push real-time updates, and webhooks fire on record changes for external integration. A visual workflow builder automates actions like notifications and field updates, TypeScript-based apps extend the platform with custom logic and frontend components, and email and calendar sync pulls Gmail messages and meetings onto contact timelines so communication history sits next to the record. The stack is NestJS with TypeORM, PostgreSQL, Redis, and BullMQ on the backend, React with Jotai on the frontend. Self-hosting on RepoCloud means unlimited users with no per-seat licensing - the pricing model that penalizes growing teams on commercial CRMs - and your pipeline, contacts, and deal history live in your own PostgreSQL database rather than a vendor's.
iDURAR
Quote to cash in one web application - create quotes, convert them to invoices, record payments, track customers: iDURAR is an open-source ERP and CRM platform for small and medium-sized businesses. Built on the MERN stack (MongoDB, Express, React, Node.js) with Ant Design components and Redux state management, it presents a clean SaaS-style interface that needs little onboarding. Core modules cover invoice management with PDF generation and email delivery, payment recording against invoices, quote and proforma handling, customer records, and accounting views over the resulting data. Multi-currency support and localization make it usable for internationally operating teams. Because the whole stack is JavaScript with an API-first backend, extending it - custom fields, new modules, integrations - is approachable for any Node/React developer rather than requiring a specialist ERP skill set. Deployment is straightforward via Docker with a MongoDB instance. Licensed under AGPL-3.0 with free commercial use; a hosted enterprise version exists but the self-hosted edition is fully functional.
Dolibarr
With 7,400+ GitHub stars, 280+ contributors, and 99 releases spanning 15 years of active development since 2011, Dolibarr is the modular ERP and CRM platform that scales from freelancers tracking invoices to manufacturing companies managing full production workflows — all within a single PHP application requiring only a web server and database. Enable exactly the modules your business needs: CRM with leads, proposals, and online contract signing; invoicing with customer and supplier management, credit notes, and SEPA direct debit; double-entry accounting with bank reconciliation and margin analysis; stock and warehouse management with barcode scanning, batch and lot tracking, and product variants; bill of materials and manufacturing orders with workstation scheduling; HR with employee records, leave management, expense reports, recruitment pipelines, and timesheets; project and task management with shared iCal calendars; and a ticket system with integrated knowledge base for customer support. TakePOS provides a touch-optimized point-of-sale interface for retail shops, bars, and restaurants with floor and table management, QR code self-ordering, automatic stock decrements, and Stripe terminal integration. Payment processors connect via PayPal, Stripe, and Paybox. The marketplace offers over 1,000 third-party add-ons, and the low-code Module Builder enables custom extensions without programming. Deploy via the official Docker image with MariaDB, DEB and RPM packages for Linux, or manual installation on any PHP-capable server. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.
Frappe CRM
With 3,300+ GitHub stars, 200+ releases, and v1.77 shipping in July 2026, Frappe CRM delivers enterprise CRM capabilities without per-seat licensing costs that plague Salesforce and HubSpot deployments. The Python backend running on Frappe Framework v15/v16 with MariaDB and Redis pairs with a Vue 3 frontend using Pinia state management, Vue Router, and the Frappe UI component library styled with Tailwind CSS v3. All-in-one lead and deal pages consolidate activities, comments, notes, tasks, call logs, and email history into a single scrollable view while the drag-and-drop Kanban board provides visual pipeline tracking across configurable stages. Built-in Twilio integration enables click-to-call with recording directly from deal pages, Exotel routes calls through agent mobile phones, and WhatsApp messaging connects via the Frappe WhatsApp module for conversational sales. A visual field layout editor lets non-technical users customize CRM forms, sidepanels, and grid views with real-time drag-and-drop without writing code. The Service Level Agreement engine tracks first-response and rolling-response times against configurable policies with automatic escalation. Meta integration captures leads from Facebook and Instagram ad campaigns directly into the pipeline. ERPNext connectivity extends CRM into invoicing, accounting, inventory, and purchasing with native data flow. Docker Compose deployment with a single command provisions a production-ready instance. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
Frappe Helpdesk
With over 3,200 GitHub stars, 900 forks, and backing from the team behind ERPNext, Frappe Helpdesk delivers a modern, streamlined alternative to Zendesk and Freshdesk with unlimited agents, no per-seat pricing, and full source code access under the AGPL-3.0 license. Built on the Frappe Framework with a Python backend and Vue 3 frontend using Frappe UI, the application collects customer inquiries from email, web forms, and the customer portal into a centralized ticketing queue with complete conversation history and threaded replies. Customizable SLA rules define response and resolution timelines by ticket type or team, triggering automatic alerts and escalations when deadlines approach or are missed. Assignment rules route incoming tickets to the appropriate agents based on priority, issue type, or workload balancing, while manual reassignment and transfer between teams remains available at any time. The customer self-service portal lets users submit tickets, track status, and search a knowledge base of published help articles that reduce repetitive support requests. Agents access saved reply templates for consistent, rapid responses to common queries. Custom fields, configurable workflows, and saved views adapt the interface to match each organization's support process. Real-time updates via WebSocket push ticket changes instantly to all connected agents. The PWA-compatible interface provides mobile access without a native app. Frappe Framework compatibility spans versions 15 and 16. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
Stalwart Mail
Stalwart replaces the traditional Postfix + Dovecot + SpamAssassin + calendar-server stack with one Rust binary that speaks every standard mail and collaboration protocol natively. JMAP, IMAP4rev2, POP3, SMTP, CalDAV, CardDAV, and WebDAV all run inside the same process — no glue scripts, no sidecar daemons, no version conflicts between components. The pluggable storage architecture lets operators choose RocksDB for single-node deployments, FoundationDB for distributed clusters, PostgreSQL, MySQL/MariaDB, or SQLite for the data store, S3/MinIO/Azure Blob for message blobs, and Elasticsearch or Meilisearch for full-text search, with Redis or the internal engine backing rate limiters and session state. Security features include S/MIME and OpenPGP encryption at rest, automated DKIM key generation with DNS publication, DANE and MTA-STS transport security, automatic ACME TLS provisioning, granular ACLs, rate limiting, and IP banning. The browser-based admin console manages accounts, domains, groups, mailing lists, SMTP queues, DMARC/TLS-RPT/ARF reports, and every configuration object without touching a config file, while the self-service portal at /account gives end users password reset and encryption key management. Multi-tenant support with per-tenant quotas enables hosting-platform deployments, and coordinator-less clustering via Zenoh or NATS scales horizontally by adding nodes. Deploy via Docker or the standalone binary. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL v3 licensed.
REI3
Replace the spreadsheet that quietly runs your department with a proper multi-user application that you design in a browser with REI3, a self-hosted low-code platform. Authors define their data model once, then assemble forms, lists, calendars, Gantt plans, Kanban boards, and charts around it, with form states that show, hide, or require inputs as a record moves through its workflow. Calendars create records from a drag-selected time range, Kanban cards change state by drag and drop, and bulk-update forms edit hundreds of records at once. Phones scan barcodes and QR codes through the camera, and signature pads capture drawings. Roles and record-level access policies decide who sees what, sign-in runs through LDAP, OpenID Connect, or multi-factor authentication, and end-to-end encryption keeps selected fields unreadable even to administrators. REST endpoints work in both directions, ICS feeds publish calendars, CSV moves data in bulk, and IMAP and SMTP accounts connect applications to email. A drag-and-drop PDF editor produces letterheads, labels, and documents with signatures and barcodes. More than a dozen free ready-made applications, including tickets, time tracking, IT assets, a password safe, and a CRM, install from the admin panel. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
Nocobase
CRMs, project trackers, inventory tools - NocoBase is an open-source no-code/low-code platform for building business systems like these. Its architecture is data-model driven: you define collections and relationships first, then compose any number of interface blocks (tables, forms, kanban, charts) on top of the same model, so data structure is never coupled to a particular view. The core is a microkernel where every feature is a plugin, WordPress-style; you enable official plugins, install marketplace ones, or write your own as npm packages with server and client parts. Data sources include the main PostgreSQL or MySQL database, external databases, and third-party APIs - so you can build admin panels over existing production data instead of migrating it. Built-in infrastructure covers role-based permissions down to collection, record, and field level, workflow automation with approval steps and scheduled triggers, and audit logs; a one-click switch flips between usage and configuration modes. Because custom features live in isolated plugins with a documented lifecycle, core upgrades do not overwrite your customizations, and swapping UIs never requires data migrations since interfaces sit on independent models. Written in TypeScript on Node.js, Koa, and React under the AGPL license, it is light enough for one person to run and extend - and where no-code SaaS platforms charge per seat and per app, a self-hosted instance runs unlimited applications for unlimited users at hosting cost alone.
Cordys CRM
Follow every sale from first inquiry to final payment inside one self-hosted CRM. Cordys CRM splits the lead-to-cash cycle into connected modules: leads with custom forms and one-click conversion, customers with contact records and shared follow-up among team members, and opportunities that advance through configurable stages from needs confirmation to won or lost. Quotations and contracts come next, with contracts carrying payment plans, payment records, business titles, and invoice records so every collection stays traceable. Orders link to contracts and move through a customizable status flow covering shipment requests, partial and full shipment, inspection, and completion. Approval workflows route requests to reviewers and keep an approval history, and real-time notifications reach users while they work. Administrators draw the organization chart, assign role-based permissions, configure modules and form fields without code, and review system logs. An MCP server secured with per-user API keys lets MaxKB agents search records, create leads, customers, opportunities, and contacts, log follow-ups, and update accounts, while an Agents module embeds those assistants in the CRM and CRM Skills connect OpenClaw and WorkBuddy to the sales process. Sales data can feed DataEase dashboards, WeCom, DingTalk, and Lark integrations link departments and messages to the office platforms teams already use, and the interface ships in English and Chinese. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed with FIT2CLOUD branding terms.
Krayin CRM
Krayin CRM gives sales teams a visual Kanban pipeline where leads flow through configurable stages — new, contacted, qualified, proposal, won, lost — with deal values tracked per stage, drag-and-drop transitions, and AI-powered document import that extracts contact details from uploaded PDFs, DOCs, and images without manual data entry. Built on Laravel 12 with a Vue.js frontend and MySQL database, the platform delivers complete customer lifecycle management through a two-stage contact model separating unqualified Leads from qualified Persons linked to Organizations, with a unified timeline displaying associated activities, notes, emails, and deals. The activity module schedules calls, meetings, and tasks on a drag-and-drop calendar with reminders and team assignment. A built-in product catalog supports line-item quoting with pricing and quantities. Email integration connects via SMTP, IMAP, and SendGrid parsing, linked to leads and contacts automatically. Workflow automation triggers actions on conditions and pushes events to external systems via webhooks. The dashboard visualizes pipeline performance, top customers, top products, and email engagement with pie charts and trend widgets. Custom attributes add text, number, date, boolean, and dropdown fields to any entity. Role-based ACLs manage team permissions per module. Extensions add multi-tenant SaaS, WhatsApp lead generation, and VoIP calling. Deploy via Docker Compose. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
EspoCRM
Teams tired of paying Salesforce or HubSpot per seat run EspoCRM: an AGPL-licensed PHP application with a fast single-page frontend over a REST API, covering sales, support, and marketing in one uncluttered interface. The sales core is complete - leads, contacts, accounts, opportunities with customizable pipeline stages, kanban views, calendars, meetings, and calls. Email is deeply integrated rather than bolted on: IMAP sync links messages to CRM records automatically, and mass email campaigns run with reusable templates, tracking, and Web-to-Lead forms feeding the funnel. Support teams get case management and a customer portal where clients track their own tickets and access a knowledge base. The real differentiator is the Entity Manager: create custom entities, fields, relationships, and layouts from the admin UI without code, with dynamic logic showing or hiding fields conditionally - EspoCRM is as much a business-application platform as a CRM. Formula scripting handles calculated fields and record automation in the free core; the optional Advanced Pack adds visual BPM process design and workflow rules. Role-based permissions with team and territory scoping, full-text search, reports, and a straightforward REST API for n8n or custom integrations round it out. Runs on PHP 8.3+ with MySQL, MariaDB, or PostgreSQL - unlimited users, zero per-seat fees.
Collabora Office
Real LibreOffice document engineering in the browser: Collabora Online is built by the company employing much of the former SUSE LibreOffice team - not a reimplementation. This deployment runs CODE (Collabora Online Development Edition), the collabora/code server that renders and edits documents entirely server-side while browsers get high-fidelity WYSIWYG output, so layout and formatting survive round-trips that break lesser converters. Four editors ship in one container: Writer for text documents (comments, track changes with comparison and restoration, form handling), Calc for spreadsheets (advanced formulas, macros, pivot tables, per-user sheet views, server-enforced cell protection), Impress for presentations, and Draw for Visio-class diagrams. Format compatibility spans DOCX, XLSX, PPTX, the ODF family, PDF, and dozens more - including Visio and Publisher import. Real-time collaborative editing supports multiple simultaneous editors with visible cursors and commenting. The architectural point: documents are processed on your server and never leave it, which is why Collabora is the engine behind Nextcloud Office and integrates with ownCloud, Seafile, and any WOPI-speaking host - or embeds in your own application via the SDK. An admin console monitors sessions and memory. For organizations that need Google Docs-style collaboration with actual data sovereignty, this is the reference open-source answer.
SOGo
SOGo adds shared calendars, address books, and a modern webmail interface to your existing Dovecot, Postfix, or Cyrus mail setup, turning familiar infrastructure into a full Exchange competitor. Rather than replacing your IMAP and SMTP servers, SOGo layers collaboration on top of them, becoming the missing link between raw mail delivery and what users actually expect from a workplace communication platform. The ActiveSync implementation synchronizes email, contacts, calendars, and tasks natively with iPhones, Android devices, and Windows without requiring users to manually configure CalDAV endpoints. CalDAV and CardDAV compliance ensures Apple Calendar, Thunderbird (via the official SOGo Connector extension), GNOME Evolution, and Android via DAVx5 all connect without plugins or workarounds. The web interface uses AngularJS Material design with responsive layouts, offering folder management, drag-and-drop calendar scheduling, contact groups, resource booking, and delegation. Shared calendars support free-busy lookups, iMIP event invitations, and per-user ACL permissions for fine-grained access across organizational units. Built on Objective-C with the GNUstep foundation, SOGo delivers exceptional performance: hundreds of concurrent ActiveSync connections from mobile devices alongside webmail and calendar traffic with sub-second response times. With 2,095+ stars and 116 releases, the project has proven its stability in production environments supporting thousands of users. The Docker deployment runs alongside PostgreSQL and memcached.
InvoicePlane
InvoicePlane manages the complete freelance and small-business billing cycle — draft quotes, convert them to invoices, automate recurring charges, collect payments through Stripe and PayPal, and generate EU-compliant eInvoice XML for automated processing by accounting systems. Deployed over 100,000 times across 193 countries, the PHP 8.2+ application on CodeIgniter 3 with MySQL or MariaDB handles everything from first estimate to final receipt. EU-compliant eInvoice generation creates machine-readable XML invoices meeting European Union standards since version 1.6.2. Recurring invoices automate periodic billing with configurable controls that pause generation when previous invoices remain unpaid. Online payment integration lets clients pay directly through Stripe, PayPal with Advanced Credit Cards, and Venmo support. The CRM-like client management module stores contact details, notes, custom fields, and complete transaction history per client. Product and task management modules let you build line-item invoices from reusable product catalogs and project tasks. Customizable PDF templates powered by mPDF support branded invoice layouts with QR codes, while email delivery via PHPMailer handles automated sending with configurable SMTP. A guest portal gives clients read-only access to view and pay their outstanding invoices and quotes. Financial reporting tracks revenue, outstanding balances, and payment history. The multi-language interface supports community translations, and multi-currency handles international invoicing. Deploy via Docker Compose with automatic database migrations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
UVdesk
For teams that answer customers by email, UVdesk is a free, self-hosted helpdesk that keeps every conversation in one shared queue. Customers have three ways in: a connected mailbox, the support portal, or a public ticket link that opens a conversation without a login. Gmail, Yahoo, Outlook, or any IMAP mailbox can feed the queue, with no limit on how many. Agents work in a threaded ticket view, where they reply, forward to a colleague, leave private notes, add collaborators, and pin important messages. Saved replies answer repeat questions, and prepared responses set a status, tag, priority, or assignment from the ticket footer. Administrators route work through groups and teams, and agent privileges decide which tickets each person may see. Workflows run events, conditions, and actions in the background, while spam settings reject senders by address, domain, or IP. A knowledge base of folders, categories, and articles, with revision history and related articles, lets customers find answers without writing in. Customers can rate the support they received, and the Kudos report lists those ratings by agent, group, team, type, priority, customer, or source. Portal branding covers a logo, brand colors, a tag line, and custom CSS and JavaScript. The community edition places no cap on agents, groups, teams, customers, or tickets. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. OSL-3.0 licensed.
jshERP
jshERP lets a small or midsize business, from a shop to a wholesaler, run purchasing, stock, sales, and money from one place instead of scattered spreadsheets. A purchase requisition becomes a purchase order, then a receipt that raises stock. A sales order becomes an outbound delivery that lowers it, or a purchase order when more must be bought in. Retail sales, returns, and serial-number scanning run through the same stock. Products sit in a category tree up to three levels deep, with barcodes, images, multiple attributes, customer-specific prices, and a base unit plus up to three secondary units. Transfers move goods between warehouses, assembly and disassembly merge and split products, and shelf locations record where each item sits. Other receipts and issues cover opening stock, stocktake corrections, and scrapped goods, while moving-average cost keeps valuation current. Finance logs income, expenses, receipts, payments, transfers, and prepayments against settlement accounts, and customer and supplier reconciliation reports export to Excel. Reports track stock levels, low-stock alerts, in-out statistics, and purchase and sales summaries, and the home page totals yesterday's and retail sales. Roles limit access down to single menus and buttons and can mask prices. A tenant model runs several businesses on one installation, and the interface switches among 73 languages. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.
Freescout
Unlimited agents, unlimited tickets, unlimited mailboxes, forever, on a $4 VPS - FreeScout's pricing inversion is why it became the most popular self-hosted Help Scout alternative, a PHP/Laravel help desk and shared inbox developed from scratch over eight years. The inbox deliberately behaves like Gmail or Outlook, so new support agents need close to zero training. The email-support core is genuinely complete: seamless IMAP/SMTP integration including modern Microsoft Exchange authentication, collision detection that warns when two agents open the same conversation, canned responses, auto-replies, internal notes, open tracking, starring, forwarding, merging, and moving conversations between mailboxes, phone-call logging, push notifications, and an auto-refreshing conversation list - plus screenshot pasting straight from the clipboard into replies. It's 100% mobile-friendly, fully screen-reader accessible, and translated into 28 languages. Beyond the core, an ecosystem of 100+ modules (mostly one-time $12-20 purchases) adds knowledge base, workflows with Gmail-filter-style automation rules, satisfaction ratings, time tracking, tags, custom fields, LDAP, Slack, WhatsApp and Telegram channels, and an API with webhooks - pay only for what your team needs. Web installer and updater included. AGPL-licensed.
OnlyOffice
With 6,800 GitHub stars and over a decade of development since its 2014 release, ONLYOFFICE Docs delivers a self-hosted Microsoft Office replacement with pixel-perfect OOXML rendering and real-time collaborative editing supporting both Fast (character-by-character) and Strict (manual save) co-authoring modes. The suite encompasses five full-featured editors — Document Editor for DOCX/ODT/EPUB/HTML, Spreadsheet Editor with 500+ functions and pivot tables, Presentation Editor with animations and transitions, Form Creator for fillable PDF forms with field validation, and PDF Editor for annotation and conversion — all operating within a unified web interface. Format support spans 50+ types including DOCX, XLSX, PPTX, ODT, ODS, ODP, PDF, CSV, RTF, TXT, and Markdown with server-side conversion between any supported pair. The JavaScript plugin API enables extending editor functionality through a marketplace of ready-made plugins for ChatGPT integration, speech-to-text, OCR, Zotero citations, and Thesaurus. Ready-to-use connectors integrate with Nextcloud, ownCloud, Seafile, Moodle, Odoo, Confluence, SharePoint, Alfresco, Liferay, and Chamilo, while WOPI protocol compliance enables integration with any WOPI-compatible platform. JWT authentication secures all API communications between host applications and the document server. Deploy via Docker with a single command or DEB/RPM packages on Ubuntu, Debian, CentOS, or RHEL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GNU AGPL v3 licensed.