xTuple PostBooks

PostBooks is a full-featured, fully-integrated Accounting, ERP, and CRM system, the core of the award winning xTuple ERP Suite. Built with the open source PostgreSQL database, and the open source Qt framework for C++, it provides the ultimate in power and flexibility for a range of businesses and industries of any size.

xTuple PostBooks includes the following:

Accounting (general ledger, accounts receivable and payable, bank reconciliation, financial reporting)
Sales (quotes, order entry, sales reporting, shipping)
CRM (universal address book, incident management, opportunity management, to-do lists, project management)
Purchasing (purchase orders, receiving, vendor reporting)
Product Definition (items, infinite-level bills of material)
Inventory and Distribution (multiple locations, other advanced warehouse features)
Light Manufacturing (work orders, strong support for make-to-order)
OpenRPT open source report writer

Like all xTuple products, it runs equally well on Windows, Linux, and Mac - and is fully internationalized (multi-currency, support for multiple tax structures, and multilingual translation packs maintained by our global community). PostBooks is licensed under your choice of CPAL, the OSI-certified Common Public Attribution License, or xTuple's commercial license.
How to get started
Getting Started with PostBooks explains how to download the software, and particularly the difference between the all-in-one PostBooks installer and the different components available for advanced users who want to set things up their own way.