Karma is definitely still useful. Violeta Ilik of a popular and useful tool for managing data in VIVO – particularly for mapping relational data to RDF. Violeta Ilik of Northwestern University has done a lot of work with Karma for VIVO and has put together YouTube videos of the mapping process.
https://www.youtube.com/channel/UCb9vsw2XvZDzZtEwe0aH9eA
...
Karma itself can be downloaded and installed using these instructions:
https://github.com/usc-isi-i2/Web-Karma/wiki/Installation%3A-Source-Code
The Karma transformation models Violeta's team uses used at Northwestern are also on Github.
https://github.com/NUBIC/R2RML-Karma
Additionally - if you are comfortable with Python, there's an example of mapping CSV to RDF for VIVO here: