4Front E-Piano is a small single sound instrument without any settings that reproduces a timbre, which is similar to DX-7 type e-piano. It is available as VSTi for Windows, and as an AudioUnit, VSTi and RTAS for Mac.
This instrument is small on memory and CPU usage and was found useful by many users and software developers as a plug & play e-piano module, which does not require any configuration or adjustment.
There is also 4Front R-Piano, which replicates a different type of E-Piano.
The Audio File 