White noise generators

Flash- or Javascript-based

• RainyMood.com
  • note: a common request is to get this in downloadable form, and though the site itself discourages this, various other people have made it available anyway
  • or you can use one of the many YouTube downloaders, to download the version that's on YouTube
• SimplyNoise.com [white, pink, brown]
• md-stuff.com/noise-generator.html
• Buddha Machine
• StormSounds / DinosaurSounds / SpaceSounds / WhaleSounds
• SleepBot.com
• endlessyoutube.com lets you loop YouTube-based ambient audio
  • Rain on the river
  • Mirage by Pete Namlook
  • binaural rain

Linux-based

• SoX / Sound eXchange — can produce brown/white/etc noise, as well as others
• Boodler — has a plugin architecture that lets it produce a wide range of soundscapes
  • it may be possible to get it to compile on Windows

Windows-based

• Audio Chaos / Soundscape Generator
• Vectormedia's
• BioHealth's Natural Ambience

Legit/free/open-source ambient recordings

• freesound.org
  • tags: soundscape, ambient
  • /~Arctura/

Ambient music

• LoungingSound.com
• SomaFM
  • Drone Zone
  • Space Station
  • Groove Salad

Wikipedia articles

• colors of noise (white, pink, brown, blue, etc etc)
• soundscape
• ambient music
• space music