It's a ROM expansion from HKA Design that adds a bunch of legendary sounds to your TR-707 or TR-727 from the TR-808, TR-909 LinnDrum, LM-1 and Oberheim DMX.
Monade has released a sample-based plug-in called Pure707. They say it's based upon the 1985 Roland TR-707 Rhythm Composer and we have no reason to doubt them. But there's also more to it than that.
Take the TR-8 Rhythm Performer, tone down the green and import your own samples and you have the TR-8S. It's not groundbreaking but it's probably exactly what we wanted for a live performance groovebox.
The namesake of Roland's 909 Day has been resurrected in the new TR-09 ACB based drum machine.
Twin decks, 808 drum machine, vocal transformer, Aria link and Serato DJ integration - this Roland DJ-808 has everything