FLIGHT COMMANDER / Eddie Benowitz / PC
Like Beats of Rage and Dungeon Craft before it, Flight Commander has made the Awesome Freeware list not so much for being a great game to play right out of the box (which, to be honest, it really isn't), but for the endless customization and modding possibilities, and the potential to build your own space combat sim from the ground up without any real programming involved.
The game is intended as an approximation of the Wing Commander games, mostly as they were during the Wing Commander 1/2/Privateer/Academy years, but with some touches carried over from the later games. It has a much nicer looking graphical engine than the old VGA games, however, yet is still pleasantly old-school enough to run with fairly low system requirements. If you're familiar with the control scheme from those older Wing Commander games you'll jump quickly into this one as nearly everything is laid out in the same way.
The game does come with a tutorial mode and fairly simple campaign to play, and there's also a simulator as in the original Wing Commander games for practicing your skills. However, the main reason to get this one is if you are more interested in making your own missions, or even a whole new game from the ground up, than playing the existing ones. Pretty much everything in the game is customizable. Graphics and music are in easy-to-convert formats such as PNG, MP3 and WAV, and the game has step-by-step instructions on how to mod the more complex aspects like creating a series of missions (complete with FMV interludes if you care to), or the scripting of how enemy ships fly.
There are some glitches and just plain orneriness to deal with. On my machine, the simulator mode would always lock Windows upon exit forcing a hard reset to get out of the game (it locked the mouse and keyboard and wouldn't respond to CTRL-ALT-DEL). The game also apparently uses different .EXEs for different aspects of the game, so when you go between the menu area, the simulator and the missions it drops you back to the desktop for a bit while it loads up the new files - it doesn't really affect gameplay but it is a bit jarring. Also, the included missions seem to start out with the enemy in Ultimate All Over Your Ass Mode right from the beginning, so if you need an introduction or re-introduction to the gameplay, and the sim isn't working, you can kind of be left cold in terms of getting into the game.
The game has actually been worked on as a project by a fan for several years now, and there can apparently be some long draughts in between updates, but work is still being done on it and the most recent update (version 1.6) appears to have just been released back in February of this year. The forums also seem to be pretty active, and there's a number of mods and conversions in progress, such as a complete remake of the original Wing Commander for this engine. The author also offers the source code upon request.