LSP Kompressor – Compressor plugin series is a free compressor VST, LV2, Ladspa plugin developed by Linux Studio Plugins Project. Compatible OS(s): Linux.
This plugin performs compression of stereo input signal. Flexible sidechain-control configuration and additional sidechain inputs are provided. Different types of compression are possible: downward, upward and parallel. Also compressor may work as limiter in Peak mode with high Ratio and low Attack time.
http://lsp-plug.in/