TwistedWave

TwistedWave is a browser-based audio editor. You only need a web browser to access it, and you can use it to record or edit any audio file. All the audio is stored and processed on the server, so you don't need to download anything, or save your work when you are done. Close your browser window and your work is saved. Open TwistedWave somewhere else, and all your audio files, with the complete undo history, are still available.