They're pretty cool modern foreign languages units which can be taken in many, many different ways at loads of different points throughout the year.
All the languages you'd expect are offered, but there are also quirky ones in the mix - I think you can even do Cornish!
They are graded from grade 1 to grade 17 (I think), with grade 9 being roughly GCSE standard, 12 A(S) standard, and anything higher than that being supposedly like doing a tiny unit at degree level.
It's usual to do them in certain specific skills (speaking, listening, reading, writing), and few centres offer speaking since there is training and extra costs for this.
These can be done internally or externally usually (except for post-grade 12 I think), and there are lots of checks done on the internally-assessed exams).
Yet some candidates will want to do all four skills at, say, advanced level (grades 10 to 12), and there is a certificate for this, and it makes it a bit more like doing a normal languages qualification.