Released on May 3, 2012, the Virtual Drumline 2.5.5 Library Update is a paid update providing a completely reformatted library, designed for Kontakt 4 or greater. This provides faster load times, improved memory management, and increased polyphony performance. This update also includes 13 new instruments, improved/updated documentation, numerous bug fixes, and allows existing VDL 2.5 users to do a 'Fresh Install' of VDL without needing to run other outdated installers.
Version 2.5.5 is a paid update for VDL 2.5.0, 2.5.1, and 2.5.2 users.. It is not required. Users of earlier versions who don't wish to update can still access older library updates if they wish. If you purchased a downloadable version of Virtual Drumline, you most likely already have the 2.5.5 version and do not need to purchase an additional update. If you're unsure which library version you're using, this article describes how to find out.