Why we like Make Beliefs Comix:
It is free
No login is required
It is web based and can be used on Mac/PC
You can upload screenshots of your comic to your blog or website
Students can be creative with this tool
It is very easy to use
It can be used by students of all ages and in all subject areas
Comics can be written in languages other than English, including Spanish, French, German, Italian, Latin and Portuguese.
Check out this FREE, open-source Minecraft clone (currently available only for PC and Linux): http://minetest.net/ - I am playing it right now. It's NOT Minecraft, but, it's pretty slick. And yes, it's totally free.
Shape Collage is a nifty free utility available for PCs, Macs, and Linux. There are limitations to the free version - most notably, you can't save save & reopen projects (click here for the list of features available in the $25 Pro flavor) - but it's super easy to use and the results are fantastic. Highly intuitive, the menus are simple to navigate, featuring clear options incorporated into a well laid-out workspace. It just feels natural, encouraging you to try different settings to see the result. This YouTube video does a terrific job explaining the program and its features. It's absolutely worth the download to explore for yourself.
MPEG Streamclip is a powerful free video converter, player, editor for Mac and Windows. It can play many movie files, not only MPEGs; it can convert MPEG files between muxed/demuxed formats for authoring; it can encode movies to many formats, including iPod; it can cut, trim and join movies. MPEG Streamclip can also download videos from YouTube and Google by entering the page URL.
You can use MPEG Streamclip to open and play most movie formats including MPEG files or transport streams; edit them with Cut, Copy, Paste, and Trim; set In/Out points and convert them into muxed or demuxed files, or export them to QuickTime, AVI, DV and MPEG-4 files with more than professional quality, so you can easily import them in a DVD authoring tool, and use them with many other applications or devices.
Supported input formats: MPEG, VOB, PS, M2P, MOD, VRO, DAT, MOV, DV, AVI, MP4, TS, M2T, MMV, REC, VID, AVR, M2V, M1V, MPV, AIFF, M1A, MP2, MPA, AC3, ...