This freeware program allow you to see into the big files in games like Quake 2 (go look in the BaseQ2 sub directory, see the big PAK0.PAK file, that's one) and extract files to anywhere you want easily.
It do not support as many game file formats as other tools, but it do support a little bit over 80 different file formats (which represent more than a 100 games).
It is plugin based for the 3 main parts of the tool: Reading/extracting (=Drivers plugins), Searching (=HyperRipper plugins) and Converting (=Convert plugins).
This program is open source since version 5, you can check the sources via CVS or for main releases as a .tar.bz2 file from this Dragon UnPACKer Sourceforge page.
The main website can be reached here: Dragon UnPACKer at ElberethZone.net
Information about plugins:
Drivers plugins allows the program to natively read ressource files, just open them and done. Those plugins also implement any decompression and decryption needed to extract data.
HyperRipper plugins allows the program to search for known structures in ressource files, this takes time and results are not always up to the expectations. Files found that way have a generic name but almost always accurate extension. For example you can search for embedded MP3 and OGG files to retrieve the music from games.
Convert plugins allows the program to convert proprietary file formats from the game makers to more useful formats. Example: Heretic 2 .M8 textures to .TGA files.
It was first made to open and extract files from Quake PAK files. The name of the program was therefore Quake UnPACKer. A DOS program written in QuickBASIC.
When it started supporting more game file formats it was renamed Dragon UnPACKer. Because the author (Alexandre Devilliers) was at that time the Sysop of a BBS named Gold Dragon.
Both version 2 and 3 where in development under the Windows interface when a crash disk stopped everything for quite long time. Version 2 was a first Windows try, some alpha versions where released (but mostly lost). The interface was simple and I Alexandre Devilliers) didn't like it. It was a simple list of entries in the opened files. IIRC it was written in Visual Basic 3.
Version 3 development started while version 2 was still in alpha. It was a UI rewrite with the goal to have an Explorer like interface (directories in the file at the left side and entries in the selected directory at the right). This is the same layout actually used in both version 4 and 5.
Version 4 was a total rewrite after 2 years when Alexandre Devilliers had enough courage to start again (after the *Ã‚Â£$@ crash disk). Written in Visual Basic 5.
This program was never made in the goal of modifying game files, only extraction. In version 4 was added the ability to create/edit PAK files (because there was a shareware tool named PAK Explorer which did the same thing). But that ability was lost in the migration under Delphi (v5 of Dragon UnPACKer).
Development is very slow lately due to lack of spare time of the author. But not dropped. :-)