Which version of Velocity is used for Confluence

[Stefan Kohler]

When building a plugin or theme it's good to know which version of Velocity Confluence is running.

I found an article about migrating to Velocity 1.5 for Confluence 2.8 (somewhere in 2008), but couldn't find current information.

There are some nice features in Velocity which aren't available in 1.5, but only in more recent versions.

[justindowning · Accepted solution]

Confluence 3.4/3.5 both use Velocity 1.6.1:

/confluence/WEB-INF/lib/velocity-1.6.1-atlassian-2.jar

com.atlassian.templaterenderer.atlassian-template-renderer-velocity1.6-plugin

[Stefan Kohler]

Seems you're right, but then I would expect that $myarray.get(2) would work. Maybe I did something wrong then ;-)

[CharlesA]

Just to add a note to the previous answer, the -atlassian-2 on the end of the version number indicates we've made a couple of changes to the code. In general, when we've been forced to make changes to open source projects that could not be contributed back to the project, you can find the source of our vendor branches here:

http://svn.atlassian.com/fisheye/browse/public/atlassian/vendor

The two changes we've made to Velocity are:

1. Introduce a thread-safe method cache (to fix a performance issue that is already fixed in later versions of Velocity)
2. Work around a weird JVM bug that caused Velocity to leak memory. (newer versions of the JVM do not have this bug)

Hope this random trivia helps. :)