NO$GBA ("no cash GBA") is a freeware Nintendo DS and Game Boy Advance emulator. Developed by Martin Korth
License: Freemium
Apps available for Windows
DeSmuME (YopYop DS) is a free and open source Nintendo DS emulator for Linux, OS X, Wii, AmigaOS 4, and Windows. Developed by YopYop156
License: Open Source
Apps available for Mac OS X Windows Linux