The Mellosoftron is a low latency, fully programmable virtual sampler.
In short, it turns your PC into a sampler which you can play live with a MIDI keyboard, with a sequencer or with any MIDI file player. Any sound card with a DirectSound 3 (or later) driver will do - you don't need a particular brand or model. You can edit all instrument patches and create new ones from scratch using your own WAVs as sound sources.
Since it comes with an integrated patch editor and uses the same file formats (PRGs and WAVs) as WAVmaker and the MIDInight Express, the Mellosoftron is the ideal tool for the creation of your own soft synth instruments. Add the Ace of WAV synthesizer and sound editor and you have a virtual recording studio inside your PC!