Based on the number of hits this blog is getting with the search term “Geronimo vs. WAS CE”, it appears that there is some confusion about the similarities and differences between Apache Geronimo and IBM WebSphere Application Server Community Edition (WAS CE). Thought I’d try and clear up some of the confusion…..

This shouldn’t be an “is A better than B?” discussion.

WAS CE is built using an open source product, Apache Geronimo. Like Apache Geronimo, WAS CE is free to download and use, and you can build it yourself from open source code. Unlike Apache Geronimo, WAS CE however does not carry an OSI-approved license, and as such, is not an open source product. WAS CE is built on an open source product. Developers are using WAS CE and Apache Geronimo; it all depends on what you’re need/comfort is.

If you want the newest stuff right away, then you’ll use Geronimo. If you want predictable release cycles, then WAS CE will fit the bill. If you want to modify the source code, fix bugs yourself or create a derivative work, then pick Geronimo. If you want integration with other IBM products and broad platform/database support, then take a peak at WAS CE. Both are free, or optionally, supported for a fee through IBM and others, so have at it!

From a technical standpoint the WAS CE team takes Geronimo and…


  • Jetty: because Geronimo comes in two flavors, one with Jetty as the JSP/Servlet engine, and the other with Tomcat as the JSP/Servlet engine. WAS CE only supports Tomcat.
  • Apache Derby: Derby is used as an internal data store for Geronimo, but is also exposed so that users can write their application data into Derby without having to get another database or do the integration. IBM Cloudscape is IBM’s free and supported version of Derby. I’m not the Derby/Cloudscape expert, but from what I remember, they are identical at the bits/bytes level. In any case, you get Cloudscape with WAS CE mainly so IBM can provide you support for the database. If you buy support for WAS CE, you automatically get free support for the copy of Cloudscape that comes with WAS CE; no separate contract, no separate charges.
  • Apache Directory Server: Mainly because users told us early on that they already have a ‘company mandated’ directory server. So why give them something very few are going to need/use (we do support Apache DS though).
  • Servicemix: When we first made this decision it was because customers and partners had told us to be careful to introduce technology in WAS CE that was (1) fully baked and (2) was supported in the rest of the WebSphere Application Server family of products.  Servicemix didn’t fit the bill at the time.  This one may change with future releases of WAS CE, but don’t quote me though as I don’t have a say anymore ;-)


  • Integration: Hooks into other IBM products like Rational Application Developer, WebSphere MQ etc.
  • Growth Path: migration path from WAS CE to the rest of the WebSphere Application Server family of products.
  • Bundled IBM JDK: or you can download WAS CE without a JDK. You can also use the Sun JDK. (More here…)
  • Platform Support: Support for Red Hat RHEL, Novell SLES, Red Flag Data Center, Fedora, Mandriva, AIX, Solaris, Windows XP & 2003. (More here…) NOTE: Geronimo has different binaries for Windows & Unix (including Linux & Mac OS X), but does not make an explicit OS support statement. You can try using it with any operating system you like, if it doesn’t work, try the Geronimo mailing list for help. Or if you have paid for support, see which operating systems your support provider supports.
  • JDBC Drivers: Bundles JDBC drivers for Oracle, DB2, MySQL and MS SQL Server to give you broad DB support (More here…)
  • Directory Support: Support for Apache Directory Server, IBM Tivoli Directory Server, MS Active Directory, OpenLDAP Server. (More here…)
  • IBM documentation: Docs, samples and plenty of WAS CE resources on developerWorks

As you may be able to tell, there are few major technical differences between Geronimo & WAS CE. We made the decision early on to stay as close to Geronimo as we could and still be able to give IBM customers what they expect out of an IBM product. The general WAS CE vision is to do as much work as we can out in the Geronimo community. In doing this, Geronimo users and WAS CE users get to benefit from the new features etc. (like we did with the console & Eclipse plug-in).

Hope this helped some of you out. If you have questions, just leave a comment or drop a line at savioTHIRTEEN (use the number instead of the word) at gmail.