Tournament Director for Windows implements the FIDE rating and ECF grading systems. The ECF grading is main grading system including the automatic submission of the results for ECF Grading.
Here is additional background to the ELO system on which FIDE Rating system is based.
As an aside, here are the details of the Scottish grading system
The Tournament Results Service allows you to publish tournaments results directly to the internet. The Results Service automatically creates web pages for each round and a final cross table. Anyone is welcome to submit their tournament to the results service for free!