Blue Cat's Plug'n Script

External side chain and auxiliary outputs support (up to 16 audio outputs).
Native C/C++ scripts support for optimal performance and flexibility.
KUIML 2.0 user interface language support to build custom user interfaces, with additional scripting capabilities.
New DSP scripts, delivered with full angelscript and C++ source code.
21 new custom skins included.
User documentation (html or pdf) can now be added to scripts.
Custom skins can be selected directly from the main menu.
Presets can now be selected using MIDI Program change and bank select messages (can be activated with the presets menu/MIDI Program Change item).
Last loaded preset can now be saved directly from the presets menu without having to select the file.
VST: fixed latency compensation reporting in Cubase (no need to re-enable the plug-in to update the latency anymore).

Audio Unit can now be loaded as a MIDI effect in Logic Pro X.
The user interface now displays switch buttons for boolean parameters instead of knobs.
Discrete parameter values can now be selected from a dropdown menu.
New API: scripts can now use plain strings as user input.
New API: scripts can now read and write files.
New scripts and presets: added audio player and recorder scripts and a wave file utility class.
Developers can now share their scripts on a dedicated GitHub repository.
Fixed: implemented pass-thru for MIDI events when no processing function is declared (default script for example).
Fixed: Audio Unit Synth version did not appear as an Instrument.
Fixed: script was reloaded when starting playback in Reaper, and the effect was not applied immediately.
Fixed: RTAS version could freeze Pro Tools 9 and earlier at startup.