If you thought SAP and Oracle Apps were the end of the world, the following is a list of all the Free and Open Source ERP packages. Adempiere A spinoff from Compiere http://www.adempiere.org/ Compiere Avaialble in both commercial and free licenses http://www.compiere.com/ GNUe A meta-project part of the overall GNU Project. http://www.gnuenterprise.org/ ERP5 A free ERP system based on the Zope application server. http://www.erp5.org JFire A Java based customizable free ERP https://www.jfire.org Apache OFBiz Apache open for business - An open source ERP project licensed under the Apache License Version 2.0 http://ofbiz.apache.org/ openbravo A web-based ERP system for SME released under the Openbravo Public License which is based on the Mozilla Public License. http://www.openbravo.com/ opentaps A full-featured ERP + CRM suite which incorporates several open source projects. http://www.opentaps.org/ openerp Formerly known as Tinyerp, a complete Open Source enterprise management software http://openerp.com/ xTuple Formerly OpenMFG, xTuple is available in 3 licenses Postbooks Edition (free), Standard Edition (midrange commercial) and OpenMFG edition (Fully Commercial) http://www.openmfg.com/ stoq An open source ERP+CRM framework by Async Open Source, Brazil http://www.stoq.com.br weberp Requires only a web-browser and pdf reader to use http://www.weberp.org/ The above list if not exhaustive. Please add to the list if you know of any Free ERP packages that I have missed.