The MeeBlip Anode, created by James Grahame and Peter Kirn, is cheap, open source and pretty bad ass sounding.
Here’s what Ninstrument has to say about the MeeBlip Anode:
Had a chance to check out the MeeBlip Anode and I must say it’s nice to have an envelope built into a bass module. It makes managing the patch a little easier and a lot more wiggle fun. 20 HP wide and all metal pot shafts makes this a well built module.
You can find out more about the standard version of the synth is available at the MeeBlip site. No details are available on the Euro version yet, but it’s a customized Anode, not an official MeeBlip release.