Tanks told me to post this here. Original post: http://jul.rustedlogic.net/thread.php?id=2351
Myself said:Remember Nitro Explorer? This is basically the same, but for NARC files. You'll find them in many DS games.
Same GUI and everything as NE - it's almost the same program. Created (edited?) in half an hour.
You'll need the .NET Framework 2.0 to run this. Don't post stupid questions like "what does this do". In short: it lets you change files inside NARC archives (similar in concept to a Zip file for example, but without compression).
Support for NARCs with no filenames (such as those in Pokémon D/P) is not implemented yet. I'll probably update it with this if anyone shows interest. It's 4:06am over here and I probably should be in bed, I can't even see the scrollbars in IRC properly.. Not tested much, so make backups of your NARC files before editing them.
Download: http://treeki.googlepages.com/NARCExplorer2.zip