iPlug 2 is a simple-to-use C++ framework for developing cross-platform audio plug-ins/apps and targeting multiple plug-in APIs with the same minimalistic code. It abstracts an audio plug-in (IPlug) and its drawing engine/GUI toolkit (IGraphics). IGraphics is a simple graphics abstraction layer with good performance which contains a collection of common controls well suited for audio plug-ins, either using bitmap or vector graphics. IGraphics can use NanoVG or Skia as the drawing backend, providing many options depending on your requirements. Alternatively, iPlug2 can be used with other UI toolkits. Examples are included showing how you can use technologies such as HTML/CSS or SwiftUI on top of a C++ DSP layer.

The recommended starting point for an iPlug2 project in 2025 can be found in a separate repo, iPlug2OOS (out-of-source)

iPlug2GPT is a customized GPT that you can use to learn how to use iPlug2.

iPlug2 API Documentation is published here and be sure to check out the iPlug2 Wiki

The original version of iPlug was released in 2008 as part of Cockos' WDL library. iPlug 2 (2018) is a substantial reworking that brings multiple vector graphics backends to IGraphics (including GPU accelerated options and HiDPI/scaling), a better approach to concurrency, support for distributed plug-in formats and compiling to WebAssembly via emscripten, amongst many other things.

iPlug 2 targets the CLAP, VST2, VST3, AUv2, AUv3, AAX (Native) and the Web Audio Module (WAM v1) plug-in APIs. It can also produce standalone win32/macOS apps with audio and MIDI I/O, as well as Reaper extensions. Windows 8, macOS 13, visionOS 26.0 and iOS 15 are the official minimum target platforms, but depending on the graphics backend used, you may be able to make it work on earlier operating systems. Windows ARM64EC builds are supported for native performance on Windows ARM devices (see ARM64EC documentation).

iPlug 2 is licensed with a liberal zlib-like license, which means that it is free to use in closed source projects and is free from corporate interference.

iPlug2 discussions happen at the iPlug2 forum and on the iPlug2 discord server - see you there!

We welcome any help with bug fixes, features or documentation.

You can help support the project financially via github sponsors. With regular financial support, more time can be spent maintaining and improving the project. Even small contributions are very much appreciated.