Hart Instruments has released HISE, a cross-platform open source audio application for building virtual instruments. HISE emphasizes on sampling, but includes some basic synthesis features for making hybrid instruments. You can build patches, design a custom interface and compile them as a VST / AU plug-in or iOS app. HISE is available as Standalone application or as VST / AU plugin for Mac OS X and Windows.
Sampler engine: fast disk streaming sampler engine using memory mapped files. Import SFZ files, Mach5 files or AIFFs with metadata from Keymap Pro. File name parser for automapping samples. multi mic sample support (with purging of single mic channels). looping with crossfades. sample start modulation. crossfade between samples for dynamic sustain samples. customizable voice start behaviour. regex parser for mapping samples. custom monolith file format for faster loading times. switch sample mappings dynamically.
Modulation: complex modulation architecture for nested modulation of common parameters. includes the most common modulators (LFO, envelopes).
C / C++ compiler: embedded C JIT compiler for fast prototyping of DSP routines (based on TinyCC). API for adding DSP modules via dynamic libraries. one click C++ build system for building VST / AU / AAX plugins (based on JUCE) from within HISE (using msbuild / xcodebuild).
License: GPL v3 or a commercial licence for closed source usage. HISE is based on JUCE, which must be separately licensed.
A powerful sampler with Disk Streaming, native multi mic support, cross fade looping, Sample Start Modulation and Round Robin groups.
Combine multiple sound generators which are capable of the most basic types of synthesis: additive synthesis, subtractive synthesis, FM synthesis, wavetable synthesis
Use Modulators like LFOs or Envelopes to change dedicated parameters (Volume, Pitch, etc.) of other modules. You can even use Modulators to modulate the parameter of another Modulator that modulates another Modulator…
Use the inbuilt audio effects including polyphonic filters and modulate their parameters.
Use the internal Macro Control System to expose only some of your internal parameters to the end user and hide the complexity of your patch. Use the WYSIWG editor to build a user interface that controls these parameters. Export the instrument as package and load it in the HISE Player.