Which ESB to choose? (95/285 technotes for 2015)

Mule ESB - 

• first successful open source ESBs 
• a commercial enterprise version is available -  offers additional functionality and support for the product
• graphical editors for an efficient implementation of integration scenarios
• connectors for B2B products such as SAP or Salesforce
• functionality of a suite is missing in Mule ESB - products from other vendors has to be used
• small community,  a restrictive licensing model and limited availability of the source code
  

Fuse ESB - 

• based on Eclipse and very intuitive.
• based on de facto standards in the integration environment such as Apache CXF and Apache Camel 

IBM ESB / IIB - 

• Based on the research by Forester - conducted by IBM - the performance and maturity of the product IBM IIB makes to significantly ahead of the game.

References:
http://www.infoq.com/articles/ESB-Integration
http://bit.ly/1JT0iz1 - in favour of IBM IIB