12 Best Open-Source ERP Systems in 2026 (Free and Self-Hosted)

If you are searching for the best open source ERP, you will find plenty of lists that rate everything five stars. This one covers 12 open-source ERP systems that are still in use in 2026, what each one is good at, where it falls short, and what it really costs to run one yourself.

A note on who is writing: Inovexa is a hosted cloud ERP, not an open-source product. Near the end we explain when a hosted system is the better call and when it is not.

What "open source ERP" actually means

Open source means the code is published under a license that lets you read, run, modify and usually redistribute it. Many of the systems below follow an "open core" model: a free community edition plus a paid edition with extra modules, hosting or support.

Three questions matter more than the label:

• Which license? Permissive licenses (Apache 2.0) let you do almost anything. Copyleft licenses (GPL, AGPL) require you to share modifications under certain conditions. LGPL sits in between.
• Which features are in the free edition? Some vendors keep accounting reports, mobile apps or the upgrade tooling in the paid tier.
• Who will run it? Someone has to install it, patch it, back it up and upgrade it. That person costs money even when the software does not.

The 12 best open source ERP systems in 2026

1. Odoo (Community vs Enterprise)

Odoo is the most widely used open-source ERP and the one most buyers look at first. It covers accounting, sales, CRM, inventory, manufacturing, purchasing, projects, HR, a website builder and eCommerce, all as separate apps you switch on.

License: Odoo Community is LGPLv3. Odoo Enterprise is proprietary and sold per user. Stack: Python, PostgreSQL, a JavaScript front end.

The split between editions is the thing to understand before you start. Community is a real, usable product, but several features people expect are Enterprise-only, including Odoo Studio, the official mobile apps and parts of the full accounting suite. Odoo's own hosting (Odoo Online and Odoo.sh) is tied to Enterprise subscriptions, so Community users self-host or use a partner.

Upgrades are the other catch. Odoo ships a major version every year, and moving a Community database with custom modules from one major version to the next is a project, not a button. The Odoo Community Association (OCA) maintains a large library of free modules and migration tools that fill many gaps.

Best for: small and mid-sized companies that want broad coverage and have a developer or partner on call. Hosting: self-hosted, partner-hosted, or Odoo's cloud if you move to Enterprise.

2. ERPNext (Frappe)

ERPNext is built on the Frappe Framework by Frappe Technologies in India. It covers accounting, stock, buying, selling, manufacturing, projects and assets. HR and payroll now live in a separate Frappe HR app.

License: GPLv3, and the full product is open. There is no locked enterprise edition. Stack: Python and JavaScript on Frappe, MariaDB as the main database.

Its strengths are a clean data model, good manufacturing basics (BOMs, work orders, job cards) and a built-in way to add custom fields, forms and scripts without forking the code. Frappe Cloud offers managed hosting from the people who build it.

Limitations: localization outside India and a handful of other countries depends on community apps of uneven quality. Advanced warehouse logic and complex multi-company consolidation need work. Major upgrades are smoother than Odoo's but still need testing if you have custom apps.

Best for: small manufacturers and distributors that want a fully open product with no paid tier to grow into. Hosting: self-hosted, Frappe Cloud, or partners.

3. Dolibarr

Dolibarr is a PHP application aimed at small businesses, freelancers and associations. It is very popular in France and Belgium. You turn modules on from a settings page: third parties, proposals, orders, invoices, stock, projects, HR leave, a basic MRP, and so on.

License: GPLv3 or later. Stack: PHP with MySQL or MariaDB (PostgreSQL is also supported).

It runs on cheap shared hosting and is easy to learn. The DoliStore marketplace sells extra modules, and DoliCloud provides official hosting. The trade-off is depth: accounting is fine for a small company but not for group consolidation, and manufacturing and warehouse features are basic.

Best for: very small businesses that want quotes, invoices, stock and projects in one place without paying per user.

4. Apache OFBiz

OFBiz (Open For Business) is an Apache Software Foundation project. It ships with accounting, order management, catalog, manufacturing, warehouse and eCommerce components, but it is better described as a framework for building an ERP than a finished product.

License: Apache 2.0. Stack: Java, Groovy, its own entity engine on top of a relational database (Derby by default, with PostgreSQL or MySQL in production).

The permissive license is the main draw: you can build a commercial product on it without sharing your changes. The downside is a dated stock interface, substantial Java work in most real deployments, and no single vendor offering support.

Best for: companies or software vendors with Java developers who want a base to build on.

5. iDempiere

iDempiere is a community fork of ADempiere, rebuilt on OSGi so that plugins can be added without touching the core. It is strong on accounting, multi-organization structures, and a configurable application dictionary that lets you define windows and fields without code.

License: GPLv2. Stack: Java, OSGi, ZK web UI, PostgreSQL or Oracle.

It handles multiple clients, organizations and currencies well, and its double-entry accounting is thorough. The learning curve is steep, the UI shows its age, and support comes from a network of independent implementers rather than one company.

Best for: distribution and multi-entity businesses with access to an experienced iDempiere partner.

6. Tryton

Tryton started in 2008 as a fork of TinyERP/OpenERP (now Odoo) and has been governed by a non-profit foundation since. It offers accounting, sales, purchasing, stock, production, projects and more as separate modules.

License: GPLv3. Stack: Python, PostgreSQL, a desktop client and a web client.

Tryton's appeal is engineering discipline. It runs on a predictable release schedule with long-term support versions, and upgrades between versions are designed to be manageable. There is no paid edition holding features back.

The ecosystem is smaller than Odoo's and the interface is plain. You will want a developer or a Tryton service provider.

Best for: technically capable teams that care more about stable upgrades than about a large app store.

7. Axelor

Axelor is a French company whose Axelor Open Suite sits on a low-code platform. It covers CRM, sales, purchasing, stock, production, accounting, HR and projects, with a studio for building forms and workflows.

License: AGPLv3 for Axelor Open Suite. Stack: Java, PostgreSQL.

The low-code tools are the main reason to choose it. Business analysts can add fields, views and BPMN workflows without Java work. Documentation and community activity are thinner than Odoo's, and much of it is French-first. The AGPL license also matters if you plan to offer a modified version as a hosted service.

Best for: mid-sized French-speaking companies that want to configure processes heavily. Hosting: self-hosted or through Axelor and its partners.

8. metasfresh

metasfresh comes from metas GmbH in Germany and is another descendant of the ADempiere code base, heavily reworked. It is used mostly in wholesale, distribution and food businesses.

License: GPL. Stack: Java, PostgreSQL, a web UI alongside the older Swing client.

It handles high order volumes, EDI, traceability and procurement contracts well, which explains its following in food trading. Outside German-speaking markets the partner network is small, and some documentation assumes German context.

Best for: wholesalers and food distributors, especially in the DACH region.

9. ADempiere

ADempiere was forked from Compiere in 2006 and is the ancestor of iDempiere and metasfresh. It is still maintained, with work on a newer web interface.

License: GPLv2. Stack: Java, PostgreSQL or Oracle.

It shares the strengths of its family, but most of the community energy moved to iDempiere years ago. If you are starting fresh, compare the two directly.

Best for: organizations already running ADempiere, or working with a partner who specializes in it.

10. Openbravo

Openbravo, from Spain, was one of the best-known web-based open-source ERPs in the late 2000s. Since then the company has shifted to a commercial, cloud-based retail and point-of-sale platform. The community ERP edition still exists, but it receives little new development.

Stack: Java, PostgreSQL or Oracle, web UI.

For a new general ERP project in 2026 we would not start here. Its history is a useful warning: an open-source product can change direction when the company behind it does.

Best for: retailers evaluating Openbravo's commercial platform, or companies maintaining an existing install.

11. xTuple (PostBooks)

xTuple, based in the United States, offers a free open-source edition historically called PostBooks, plus paid Distribution and Manufacturing editions. The free edition covers accounting, CRM, sales, purchasing and basic inventory.

License: the open edition is under the CPAL. Stack: PostgreSQL with much of the business logic in the database, a Qt desktop client and a web client.

The accounting is good, and putting logic in PostgreSQL makes reporting straightforward. Manufacturing features such as MRP sit in the paid editions, and localization is US-centric.

Best for: small US distributors and light manufacturers that are comfortable with a desktop client.

12. LedgerSMB

LedgerSMB began in 2006 as a fork of SQL-Ledger. It is accounting-first: general ledger, AR, AP, invoicing, basic inventory, quotations and orders. It is not a full ERP, and it does not pretend to be.

License: GPLv2. Stack: Perl, PostgreSQL.

It is a sensible choice when your real need is reliable bookkeeping with some order handling and you want your data in a well-structured PostgreSQL database. It has no manufacturing, CRM or HR to speak of.

Best for: small firms that need open-source accounting more than a full ERP.

Comparison table

The true cost of a "free" ERP

The license fee is zero. The project is not. Here is where the money goes, roughly in the order you will meet it. We cover the general version of this in our piece on hidden ERP costs, but open source shifts the weight in specific ways.

• Hosting. A server, a managed database or a VPS, plus offsite backups and monitoring. Small for one company, but it never stops, and someone has to be responsible when the disk fills up on a Friday night.
• Implementation. Setting up the chart of accounts, tax rules, warehouses, units of measure, price lists and user roles, then migrating opening balances and master data. This is the same work as with a commercial ERP, and it is usually the largest single cost. Our implementation timeline guide shows what a realistic schedule looks like.
• Customization. Open source makes it easy to change the code, which makes it easy to change too much. Every custom module is something you will have to port to the next version.
• Upgrades. This is the cost most teams underestimate. With Odoo Community, for example, skipping two or three major versions and then trying to catch up can mean weeks of developer time. Budget for upgrades every year, or accept that you will stay on an old version.
• Security patches. You apply them, test them and schedule the downtime. Nobody does it for you.
• Support. Community forums are helpful but have no response time. When payroll will not post the day before payday, you want a contract with someone.
• Local compliance. E-invoicing formats, tax reports and statutory accounts change by country and by year. If your country's localization is maintained by two volunteers, that is a risk you are taking on.

A practical test: price three years of a self-hosted install, including implementation and one upgrade, against three years of a hosted subscription. Sometimes open source wins clearly. Sometimes the gap is much smaller than "free" suggests.

When open source is the wrong choice

Open-source ERP is a good fit when you have technical people, specific processes that off-the-shelf software handles badly, and a reason to own the code. It is a poor fit in these situations:

• No one in-house can own it. If your plan is "the accountant's nephew will set it up," expect trouble in year two.
• You need it running in weeks. A self-hosted install that is configured, migrated and tested takes longer than most teams expect. Our list of common ERP implementation mistakes covers why.
• Your country's localization is weak. Check who maintains the tax and e-invoicing modules for your country and when they last released.
• You want predictable costs. Self-hosting turns a fixed subscription into a series of variable bills for servers, developers and upgrades.
• Auditors or customers ask for certifications. You become responsible for documenting security controls on the servers you run.

When a hosted modular cloud ERP makes more sense

To be clear, Inovexa is not open source. It is a cloud ERP built in Tunis, Tunisia, and part of MSAI Systems. We host it, patch it and upgrade it. You do not get the source code, and you cannot fork it. If owning the code matters to you, one of the 12 systems above is the right direction.

Where a hosted option like ours tends to fit better is when the reasons people choose open source are really about cost and flexibility, not code ownership:

• You only want to pay for what you use. Inovexa has 11 modules (Dashboard, HR, Finance, Supply Chain, Production, Purchases, Sales & CRM, Logistics, AI Engine, Reports, Analytics) on one database, and you pay for the modules you deploy. That is the same idea as switching on apps in Odoo or Dolibarr, without running the server. Our article on modular ERP explains the approach.
• You do not have an IT team. A typical standard setup takes about 48 hours. There is no upgrade project to plan.
• You run several entities or currencies. Multi-currency and multi-entity are built in rather than added through community modules.

Inovexa is used by more than 340 companies in over 12 countries. It is not the right choice for everyone, and for a company with strong developers and unusual processes, a well-run Odoo or ERPNext install can be the better answer. If you are unsure, our step-by-step guide to choosing an ERP is a neutral place to start.

Frequently asked questions

What is the best open source ERP for a small business?

For most small businesses the shortlist is Odoo Community, ERPNext and Dolibarr. Dolibarr is the simplest to run. ERPNext is fully open with no paid tier. Odoo has the widest range of apps, but some features are in the paid Enterprise edition.

Is Odoo really open source?

Odoo Community is open source under LGPLv3. Odoo Enterprise is a proprietary, paid edition with extra features such as Studio and the official mobile apps. Many companies start on Community and later move to Enterprise.

Is ERPNext completely free?

The software is free and licensed under GPLv3, with no locked features. You still pay for hosting, implementation and support, either to Frappe through Frappe Cloud, to a partner, or in your own staff time.

Can I self-host an open-source ERP on my own server?

Yes. All 12 systems in this list can be self-hosted. You become responsible for backups, security updates, uptime and version upgrades, so plan for that work before you install.

How much does an open-source ERP cost to run?

The license is free, but hosting, implementation, customization, upgrades and support are not. Implementation is usually the largest cost. Compare three years of total cost, not license price, before deciding.

Is Inovexa an open-source ERP?

No. Inovexa is a hosted cloud ERP. You do not get the source code. You pay for the modules you deploy, and we handle hosting, updates and upgrades.

Further reading & sources: Odoo editions · ERPNext · Dolibarr · Apache OFBiz · Tryton · iDempiere.