Heres a great release for retro emulation fans:

Z64K NewUI (2018/02/04) is released. Pixel exact emulation of the Commodore 64, VIC 20 and Atari 2600 written entirely in Java. The emulators should run on any platform with an updated java runtime environment installed.

Z64K Changelog:
4 February - NewUI
Updated mapping of VDC RAM to match real C128 when register 28 is set to 16KB mode.
29 January - NewUI
Included some screenshot options via capture tab in screen settings
D030 tester updated to Version1.3 (see link below)