Church offices juggle member directories, giving records, event rosters, and volunteer schedules, and ChurchCRM, a free church management system, brings all of it into one browser-based workspace. Administrators keep a record for every person and family, with contact details, roles, notes, custom properties, and a timeline, while visitors submit a self-registration form that staff approve before it reaches the printed directory. Treasurers log donations against family pledge accounts, follow numbered giving envelopes and multi-year pledges, and batch gifts into deposit slips with printable bank forms. Ministry leaders organize teams, committees, Bible studies, and Sunday School rosters, then schedule volunteers into positions with substitutions and reminder email. Events can be one-time or recurring, appear on month, week, day, and list calendars beside birthdays and anniversaries, and collect attendance through kiosk tablets that alert parents by email or SMS. Members sign in to a portal to update their details, confirm their household, and check the church calendar and their volunteer schedule. A family map shows where households live and which ones are close by. Reports produce directories, mailing labels, birthday lists, financial statements, and custom queries, while CSV import, an Export Hub, and one-click database restore handle moving data. Role-based permissions and two-factor sign-in protect sensitive records, and plugins add MailChimp and Vonage SMS. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Admidio is membership management software for clubs, associations, and groups, built so that every permission follows from the roles a person holds. Organizers define roles such as board, youth team, or trainers, decide who may email or see each one, and grant module rights like managing events, editing contacts, or uploading photos with simple switches. Contact records use customizable profile fields, record relationships such as parent and child, and can be imported in bulk or exported as vCards. New members register online and administrators review each request. Events carry dates, venues, calendars, and participant lists with sign-up, and the schedule downloads as iCal. Messages go as HTML email to individuals, roles, or groups, and members also find announcements, a categorized forum, document folders with role-based access, and photo albums with e-cards. The inventory manager tracks equipment, who holds it, and its borrowing history. Optional two-factor login protects accounts, a change history can be switched on for every module, and single sign-on lets other applications authenticate against the member database. Twenty-five languages are included, the interface installs as a progressive web app, and sub-organizations can be managed from the same installation. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-2.0 licensed.

Running a school means juggling lesson plans, timetables, attendance, behaviour notes, and grades all at once; Gibbon gives teachers, students, parents, and administrators one shared web system for that daily work. Teachers build lessons from reusable Smart Blocks, assemble them into units with learning outcomes, set and collect homework online, and grade the results in a colour-coded markbook that stays linked to every class. The timetabling engine builds schedules from reusable day structures, ties them to real calendar dates, handles exceptions, books rooms and facilities, and shows every student and teacher exactly where they should be. Attendance can be taken by form group, class, or individual student, with future absences recorded ahead of time and reports ready for emergencies or truancy follow-up. Behaviour records log the good alongside the bad using your school's own descriptors and severity levels, notify form tutors when something needs attention, and surface patterns across a student's history. Each student's profile pulls timetable, attendance, behaviour, library, and assessment information into one page, while activities sign-ups, a school-wide resource library, and departmental scope-and-sequence views keep the wider community connected. Because every module can be switched on or off per role and extended with community modules, the same platform fits a small primary school and a large secondary school in 26 languages. 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.

Yoga studios, comedy clubs, choirs, and bands use Revel to sell tickets, memberships, and season passes from their own server with no platform fee. Studios and clubs sell monthly or yearly memberships through Stripe and offer series passes that cover a class pack, a course, or a season, with wallet cards that a door scan verifies. Venues design seat maps with sectors, individual seats, and accessible seats, and buyers pick seats on an interactive map while the seats are held at checkout. Bands and DJs sell their own shows with no promoter in between, set pay-what-you-can tiers, open presales to invitation-link holders, and export every buyer's name and email. Communities that vet who comes screen requests with questionnaires reviewed automatically, manually, or both, and keep private guest lists, invitation-only events, and a fuzzy-matched blacklist. Buyers check out a multi-tier cart without an account, using discount codes and fixed-price, free, or pay-at-the-door tiers. Tickets arrive as QR PDFs or Apple Wallet and Google Wallet passes, and door staff check guests in by scanning. Organizers run waitlists with time-limited offers, announcements, reminders, and a Telegram bot for RSVPs and invitations. Revenue and VAT reports export as XLSX or PDF, and VIES checks buyer VAT IDs. The web app speaks English, German, Italian, French, Spanish, and Portuguese. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Roughly 40 integrated business apps forming a full ERP: Odoo's open-source suite runs companies end to end. The Community Edition, licensed LGPL-3.0, ships roughly 40 apps covering CRM, sales, invoicing, basic accounting (journals, chart of accounts, taxes, reconciliation), inventory and warehouse management with multi-step routes, manufacturing with BOMs and work orders, purchasing, project management, timesheets, HR, a website builder, and eCommerce. Each app works standalone, but they share one PostgreSQL database and one data model, so a confirmed sale updates stock, triggers procurement, and posts invoices without integration glue. The modular design means you enable only the apps you need and extend with 40,000+ community modules from the Odoo app store covering nearly any vertical requirement. Inventory supports multi-warehouse stock, reordering rules, and lot and serial tracking with barcode-ready operations; manufacturing ties BOMs, work orders, and work-center routing directly to sales demand and stock levels; and the website builder sells straight from your product catalog with payment provider integrations. You can start with just CRM and invoicing on day one and switch on inventory or eCommerce later - new apps integrate with existing data instantly because the schema is shared. The server is Python with an XML/JavaScript view layer, and because data lives in plain PostgreSQL there is no proprietary format: you can query, back up, migrate, and extend business data directly, with unlimited users and no per-seat licensing - where enterprise ERP pricing is per user per month, headcount here costs nothing.

Salesforce's platform model, 100% open-source (Apache 2.0): Corteza is a Go/Vue.js low-code platform developed under a foundation, so there is no open-core bait to grow out of. The heart is Corteza Compose: namespaces contain applications, modules define record structures the way Salesforce objects do, and a drag-and-drop page builder assembles record pages, list pages, dashboards, and charts from configurable blocks. Automation comes from a visual, BPMN-style workflow engine plus JavaScript automation scripts, so cross-application business logic - approval chains, field updates, notifications - is configured rather than programmed. Granular role-based permissions reach down to individual modules, fields, and records, mirroring real organizational hierarchies. Corteza CRM ships as the flagship application built entirely on Compose: leads, accounts, opportunities, campaigns, and cases with a 360-degree customer view, covering most Salesforce standard objects - and because it is just a Compose app, adding or reshaping modules is configuration, not a fork. Everything is reachable over REST APIs, deliberately familiar tooling eases Salesforce admin migration, and a CLI can even generate synthetic records for load-testing what you build.

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.

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.

With over 37,800 GitHub stars and active development since its first release in 2008, ERPNext is the most-starred open-source ERP system — delivering accounting, inventory management, manufacturing, CRM, project tracking, asset management, HR, and point-of-sale capabilities through a unified web interface built on the Frappe Framework's metadata-driven architecture. The accounting module handles multi-company consolidation, multi-currency transactions, tax templates for GST and VAT, bank reconciliation, and automated journal entries with real-time profit and loss, balance sheet, and cash flow reporting. Manufacturing covers production planning with multi-level bill of materials, work order scheduling, capacity planning, subcontracting, and quality inspection at each production stage. Inventory tracks stock across multiple warehouses with batch and serial number tracing, automatic reorder levels, landed cost calculations, and perpetual inventory valuation using FIFO or moving average methods. The CRM module manages leads, opportunities, and customer communication with email integration, while project management tracks tasks, timesheets, and Gantt-based scheduling with budget controls. Custom applications extend functionality through the Frappe ecosystem without forking the core codebase, and the REST API enables integration with payment gateways, shipping providers, and third-party services. Deployable via Docker Compose or the bench CLI tool with MariaDB and Redis. 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.

A campaign engine wrapped around a contact database: Mautic, the largest open-source marketing automation platform, replaces HubSpot or Marketo without per-contact pricing. Contacts arrive through forms, landing pages, imports, or the REST API and flow into segments: dynamic filters that update automatically from behavior, custom profile fields, or point scores. Segments decide who qualifies; campaigns decide what happens. The drag-and-drop Campaign Builder composes multi-step workflows from actions, positive/negative decision trees, and conditions (field values, tags, device type, segment membership, point thresholds), with static or relative delays, a Jump-to-Step action for moving contacts between branches, and handoffs that push contacts into CRMs or entirely different campaigns. Messaging covers email, SMS, and web/app push out of the box, with A/B testing and a drag-and-drop email builder; dynamic website content swaps page sections per known contact. Lead scoring assigns points for clicks and visits with decay for inactivity, while stages track funnel position. Native integrations cover Salesforce, HubSpot, Zoho, and Dynamics, plus a full REST API for custom sync. It runs on PHP and MySQL with cron jobs processing campaigns and segment rebuilds - self-hosting keeps your entire contact database and behavioral history under your control.