Open303 is a free and open source emulation of the famous Roland TB-303 bass synthesizer for the VST plugin interface (VST is a trademark of Steinberg Media Technologies GmbH).
Get an older version of the VST 3 Audio Plug-Ins SDK that includes the complete VST 2 SDK and extract it. Copy the files from VST_SDK/vst2sdk/public.sdk/source/vst2.x/ and VST_SDK/VST2_SDK/pluginterfaces into Libraries/vstsdk. The structure of the Libraries/vstsdk directory needs to be as follows:
Libraries/vstsdk/
├── pluginterfaces
│ └── vst2.x
│ ├── aeffect.h
│ ├── aeffectx.h
│ └── vstfxstore.h
├── aeffeditor.h
├── audioeffect.cpp
├── audioeffect.h
├── audioeffectx.cpp
├── audioeffectx.h
├── CMakeLists.txt
└── vstplugmain.cpp
Now create a directory CMake in the Build directory in the root of the project, cd into that directory and run cmake ../.. && make. Copy the resulting open303.so file to a place where your DAW can find it, generally that would be ~/.local/lib/lxvst/.
git clone https://github.com/autostatic/open303.git
cd open303
wget "https://web.archive.org/web/20181016150224/https://download.steinberg.net/sdk_downloads/vstsdk3610_11_06_2018_build_37.zip" -O Libraries/vstsdk/vstsdk.zip
unzip Libraries/vstsdk/vstsdk.zip -d Libraries/vstsdk/
cp Libraries/vstsdk/VST_SDK/VST2_SDK/public.sdk/source/vst2.x/* Libraries/vstsdk/
cp -a Libraries/vstsdk/VST_SDK/VST2_SDK/pluginterfaces Libraries/vstsdk/
cmake -B Build/CMake
cmake --build Build/CMake
cp Build/CMake/open303.so ~/.local/lib/lxvst/
Thanks to the Airwindows repository for these instructions!
Load the solution-file Open303.sln (in the folder 'Build/VisualStudio2008') with Microsoft Visual Studio 2008 and try to build the plugin. If it works, you will find the results of the compilation (the final .dll and some intermediate files) in the subfolder 'Debug' or 'Release' of 'Build/VisualStudio2008', depending on whether you selected a debug- or release-build.
Load the CodeBlocks project file Open303.cbp (in the folder 'Build/CodeBlocks') - and build away. The results will be found in the subfolder bin/Debug or bin/Release. On my setup, i get 15 compiler warnings which are all rooted in source files of the VST-SDK (not the Open303 code itself) - so i guess we may safely ignore them.