WaveShop




    Bit-perfect: samples aren't changed needlessly
    Very fast: all processing is done in memory
    64-bit version can edit files exceeding 4GB
    Supports most file formats including AAC/MP4, MP3, FLAC and Ogg/Vorbis
    Clipboard: Copy/Cut/Paste/Insert/Delete
    Unlimited undo
    Normalize and/or fix DC offset
    Amplify (boost/attenuate)
    Fade in/out/custom, linear or logarithmic
    Peak statistics
    RMS statistics with histogram
    Reversal and inversion
    Find clipping with detailed report
    Extract channels to mono files
    Insert/delete/swap channels
    Change audio format
    Sample rate conversion
    Generate audio w/ envelopes and modulation
    Edit surround speaker assignments
    Find zero crossing
    Multiple Document Interface (MDI)
    Multithreaded processing
    Playback via DirectSound
    Peak-hold meters with surround support
    Real-time spectrum analyzer
    Recording with no limit but disk space
    One-touch and sound-activated recording
    EQ, compression, and other effects via LADSPA plugins

http://waveshop.sourceforge.net/download.html