The ADempiere project began in in September 2006 as a solution to ongoing philosipical differences with the delvelopment team at Compiere. Frustrated with commercial aspects and goals at the Compiere project, the developers behind aDempiere sought a more robust and impassioned technology sharing and leveraging effort, rather than concentrating on the freezing of the standards and building of the installed base which may well have been the more important focus at Compiere.
ADempiere is based on JBOSS and the JVM client platforms interacting with databases such as PostgresSql. Sourceforge hosts a client download for Windows which is a package of the ADempiere java based business logic, the JDK and a PostgresSql installation. The ADempiere client can be configured to interface with Linux servers running the Oracle database, so scalability is wide ranging. Instructions for installing the client on Mac, Ubuntu or Fedora are available here.
ADempiere boasts modules for Quotations, Proposals, Sales Orders, Work Orders, Invoicing and Shipping. Also Purchasing, Requisitions, Receiving, Vouchers. Also Bills of Materials, Warehouse, Physical Inventory, forecasting, discrete manufacturing, maintenance and costing.
Adempiere also contains General Ledger, Accounts Receivable, Accounts Payable, Human Resources and even boasts of CRM, POS and ecommerce. Likely these are more of restful capabilities to meet other solutions.