Sharp

EmuZ-2500
An open source MZ-2500 emulator for Windows by the Unofficial Nester Author Toshiya Tekada.
http://www1.interq.or.jp/~t-takeda/mz2500/

EmuZ-2800
Open source MZ-2800 emulator for Windows.
http://www1.interq.or.jp/~t-takeda/mz2800/

Mz800em
An open source MZ-800 emulator for Linux/svgalib based on Mz700em written by Russell Marks.
http://www.math.uni-magdeburg.de/~mkoeppe/mz800/

POEMS
An open source PC-xxxx emulator for FreeBSD and Linux. [English/Japanese]
http://sourceforge.jp/projects/poems/

Virtual X68000
An open source X68000 emulator for Linux.
http://www.vx68k.org/vx68k/