Updates to Portal have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Fixed screen “fuzziness” caused by color correction operation

Fixed text not rendering in game if font Tahoma was disabled

Fixed startup video not playing fullscreen

Added optional -snd_openal command line parameter to force the engine to use the OpenAL api, can be used if Portal is playing no audio when launched normally

Added mac_fsbackground convar, on Snow Leopard or better you can set this to have Portal still visible when it is not the foreground application

Source Updates to Portal have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Fixed screen “fuzziness” caused by color correction operation

Fixed text not rendering in game if font Tahoma was disabled

Fixed startup video not playing fullscreen

Added optional -snd_openal command line parameter to force the engine to use the OpenAL api, can be used if Portal is playing no audio when launched normally

Added mac_fsbackground convar, on Snow Leopard or better you can set this to have Portal still visible when it is not the foreground application

Source