The Pro 52 is a soft-synth that reproduces the sound of the Sequential Circuits Prophet-5 analog synthesizer. The Pro 52 is made by Native Instruments, a German company that produces software based synthesizers.
The Pro 52 really does sound great, and faithfully reproduces the various sound qualities that usually only analog equipment can create. It can interface with most modern audio sequencers using VSTi, DXi, MAS, and Directconnect standards. It can also work as a standalone application that responds to MIDI signals.
Some technical specs:
With retail price of 299$, it's slightly cheaper than it's vintage hardware version.