Dave,
There is no native Linux implementation of VARA. However, Ardop is an alternative for HF Winlink. Ardopcf () is an open source multi-platform implementation of Ardop that I maintain.
The performance is not as good as VARA, and it has some bugs that I'm still working on, but it is usable on both Linux and Windows. It pairs well with Pat (), the open source multi-platform Winlink client. These both also run well on low end hardware including the Raspberry Pi Zero.
Peter LaRue
AI7YN
