A project I’ve been working on in my spare time the last 2/3 weeks is a program called Ascii Paint. Ascii Paint is a simple open source painting program which uses ASCII characters instead of pixels. Ascii Paint was started by Shafqat Bhuiyan & Jice, but I heavily adapted it, adding, amongst other things, a more refined UI, export to animated gif, palettes, layers, and a better file format.
Ascii Paint can be used to make ascii art, mockup scenes from roguelikes, or even to make ascii animations. You can download the program, read a tutorial, and check out the source at the ascii-paint project site.