The TrueZIP project has released versions 5.18 & 6.2. They write in, "For 6.2 the primary focus has been to optimize multithreading performance, fix minor bugs and enhance the Javadoc. Updating is recommended for multithreaded environments such as application servers. For TrueZIP 5.1.8, this is a bug fix release. It also marks the End Of Life for TrueZIP 5 as TrueZIP 7 has entered the design phase and maintenance of then three releases takes too much resources."