ABL3 is a VST emulation of the classic TB-303 acid synthesizer from Roland. It's recently been upgraded to 3.3.0 and has a host of new improvements:
AudioRealism Bass Line 3 (ABL3) is the next generation of our critically acclaimed 303 emulation plug-in. ABL3 is a complete redesign from scratch and has been in development for several years with the goal of creating the most authentic emulation possible. With an intuitive and streamlined workflow we hope ABL3 will set a new benchmark in software 303 emulation.
The latest version (3.3.0) includes an improved diode ladder simulation as well as improve accent modelling, including optional engine defects such as malfunctioning slide and accent capacitors
The full version of ABL3 costs £89.16 and is available in VST and AU formats here.