If you are looking for ERP solution, Please have a look at this:
iDempiere. Community Powered Enterprise, also known as OSGi + ADempiere, is an open source Enterprise Resource Planning (ERP) software that is fully navigable on PCs, tablets and smartphones, it also has customer relationship management (CRM) and supply chain management (SCM) functions.
In case you need only Middleware kind of message sending and integration then Mulesoft is good.
Please tell your need.