The Linux Audio Developer's Simple Plugin API or LADSPA is a free interface for audio effects and filters in Linux. LADSPA plugins process audio signals and are used for example for effects such as reverb, chorus or delay. The DSSI interface that is used for virtual instruments, is based on the specification of LADSPA. LADSPA replaced proprietary systems such as VST Steinberg on Linux.
Successor of LADSPA is based on LADSPA LV2 interface.