A .PK3 file is a renamed ZIP file, used in games based on the Quake III engine. It usually contains a checksum to prevent the opening and recompression of the file, or the addition of extra maps to demo versions. The .PK3 file contains the maps, models, textures, weapons, sounds, scripts and other assets for the game.
They can usually be viewed or extracted using a file archiver with support for the ZIP file format. PK3 files can be created using software designed for that purpose.
Quake Live also uses PK3 files, but these files have been encoded by means of a bitwise XOR with a string of characters and therefore cannot be opened with a regular ZIP program like other PK3 files. However, open source utilities have been created to decode these PK3 files, such as the quakelivedec program.
Games which use the id Tech 4 game engine, such as Quake 4 and Doom 3, use an identical file type, .PK4 files.
Sometimes I feel so lost S.O.S. all my lines are crossed. I bite off more than I can chew. It's killing me its killing you there's nothing that I'd rather do. It's got me now its holding me. A sign of something good a sign I thought I'd never see. I try to keep it in my head. We'll you can kick my ass and burn your books, but it won't change a word I've said. I guess I should have seen it coming. It's in the smile on his face. Did you really think that this would be so easy? I think you made a big mistake. What went so wrong? Every action has reaction in this fucked up world that you created. Now you're head is so full of negativity and shattered dreams. A world of noise you end up hating. It's got me now it's holding me. A sign of something good a sign I thought I'd never see. I try to keep it in my head. We'll you can kick my ass and burn you're books but it won't change a word I've said. I guess I should have seen it coming. It's in the smile on his face. Did you really think that this would be so easy? I think you made a big mistake. What went so wrong it's been too long. So just take it on the chin. It's who you are and what you do. Not who you were or what you have been. There's just one thing you should know. That I still care to work it out don't think about it let it go.