DOOM-PSP has been a very popular homebrew port since it's initial release, supporting various different WADs and mods. Now, StereoMike has release "DOOM-PSP v0.05" a modification of Lantus' original DOOM-PSP v0.04. Here's what StereoMike has added and fixed in this great program:

-Added Selection of PWAD to load in addition to the main (I)WAD.
PWADS should be put in a directory below the WAD directory
for example
PSP/GAME/DoomPSP
PSP/GAME/DoomPSP/WADS --put the main wads here
PSP/GAME/DoomPSP/WADS/PWADS --put the PWADS here

Select with triangle.
Can also view txt-files, scroll with Square button.

-Can now load IWADs that are not named correctly. Just assumes that it's a Doom 2 wad.
This makes for example DUKENUKEM.WAD load without having to rename it to DOOM2.WAD

-Music now works fine
Uses samples from the opensource freepats.opensrc.org
Needs these placed in the inst directory. This is included in the package.

-Compiled against latest PSPSDK

-Changed key usage to cross for selection in wad list and circle to go back.

-Changed exit screen to say "press x to exit" instead of "press y to exit"

-Fixed going back one directory by using circle button.

-Rearranged a bit in the code.

Changes in Doom-PSP v0.04 S.S b6 fix

-Fixed problem with screen alignment
Was a problem with the memory aligment of the texture.

-Increased the music volume to a normal level

Changes in Doom-PSP v0.05

-Added showing of datestamps of savefiles

-Fixed problem with changing to chainsaw and showing map

-Dehacked support (use square to select a file) Batman Doom has been tested and is working, a sample .deh file is included

A big Thank you to the author of Chocolate Doom (http://www.chocolate-doom.org/) for letting meuse his code for the dehacked support.

Oh, and Dehacked files are used for modifiying the behavior of Doom, weapon damage and rate and such things. Try out arsenal.deh to see what it's about