Portal: Vocaloid Edition, now patched for SteamPipe.
Place the folder inside in your Sourcemods, restart Steam, and there you go. Requires Portal to be installed.
Changes:
Updated GameInfo.txt
Packed sound folder into portalvocaloid_sound_vo_english.vpk
Packed models and materials folders into portalvocaloid_pack.vpk
Added icons for Steam games list, icon extracted from installer EXE.