Traktor Pro is great software with a disgusting amount of MIDI custom features like the modifier. I'm working on a Custom MIDI Mapper for the DN-HC4500 and Traktor Pro.
• ASIO4ALL: Use your internal sound card
• MP3Gain: Same Volume for all songs
• CDex: Convert CD's to MP3
• MPTrim: Remove, fade or add silence
• WinMP3Packer: Convert VBR to CBR
• Foobar2000: Great Playback Software