Seems there are bug fixes that could be important to us:
- Fix bug in #parse that threw an NPE when IncludeEventHandler returned null and inline
macros are kept local. Fixes VELOCITY-717. Thanks to Jarkko Viinamaki.  nbubna
- Fix double-checked locking in RuntimeInstance's optional lazy-init for Java 1.5+.
Users of older JREs in multi-threaded environments MUST manually call init() on any
thread-shared Velocity singleton or VelocityEngine instances to avoid race conditions. New
auto-init feature is only supported on Java 1.5+. Fixes VELOCITY-750.    nbubna
- Fix 100% CPU loop hang under simultaneous HashMap calls in ClassMap due to classic bug
in Sun's implementation. Now uses ConcurrentHashMap when available and Hashtable
otherwise. Fixes VELOCITY-718.
Thanks
-Vincent
Begin forwarded message:
  From: Nathan Bubna <nbubna(a)apache.org>
 Date: May 19, 2010 2:55:58 AM GMT+02:00
 To: Velocity Developers List <dev(a)velocity.apache.org>rg>, Velocity Users List
<user(a)velocity.apache.org>rg>, announce(a)apache.org
 Subject: [ANNOUNCE] Apache Velocity Engine 1.6.4
 The Apache Velocity Team announces the availability of the of Apache
 Velocity Engine 1.6.4. This is only a bugfix release and contains no
 new features.  We recommend all 1.6.x users upgrade to this release.
 The change log is here:
 
http://velocity.apache.org/engine/releases/velocity-1.6.4/changes-report.ht…
 Apache Velocity 1.6.4 can be downloaded here:
 
http://velocity.apache.org/download.cgi
 Documentation for Engine1.6.4 can be found here:
 
http://velocity.apache.org/engine/releases/velocity-1.6.4/
 For the Apache Velocity Team,
        Nathan Bubna