My name is Roman Vincze. I play chess (https://ratings.fide.com/profile/324906) and I'm also a programmer.
As for tournaments with swiss system, all computer programs are paid. That's why I decided to create a freeware program (REALLY free (as Lichess)). Name of my program is VinczeSwiss. The VinczeSwiss program is available for download at: https://www.zzsvysocina.cz/download/vinswiss.htm
The VinczeSwiss program is not (for now?) FIDE certified, but can be used now for tournaments without sending to ELO. The VinczeSwiss program has its own (recursive) pairing function, but can also use the external pairing engine JaVaFo.jar. When using JaVaFo.jar, the VinczeSwiss program is fully compatible with FIDE pairing rules! Languages of VinczeSwiss program: now only English and Czech (in package https://www.zzsvysocina.cz/download/vinswiss.zip, there are files english.txt and czech.txt).
If you will like the VinczeSwiss program, I would like to ask you: would a some chess player and a native speaker translate file english.txt into another language (German, Spanish, French ... ...)?
Can you use program VinczeSwiss and send me your opinion / feedback/ ideas?