Short Answer: Yes
Was Ritchie correct, or was he just being modest? As of the date of the quote (1993), were more computer languages descended from Pascal than C?
Well, it's not as easy as it sounds, as there is no birth certificate with all parents named. Both languages are Algol descendants. And throughout the 1980s Pascal was seen as the way to go - eventually all the way 'til Ada. So yes.
We are counting languages, not their specific compilers/implementations (e.g. UCSD Pascal, Borland C).
Err. No. This falls short of development. To start with, Pascal in its core definition is a very simple language (much more simple than C) intended for teaching classes about basic programming all the way to compiler building. As a result, it was so simplified that serious work was almost impossible - an elegant language for ivory tower games. It lacked strings, usable file I/O and any form of modularisation.
To make it usable for real world application, implementation had to enhance it substantially. And as usual, each and every developer had it his way. A UCSD Pascal program could not be compiled with Pascal/MT+ or Microsoft or Turbo Pascal, as all of them handled things differently.
If at all, then there is a main line promoted by the two most successful products: UCSD Pascal and Turbo Pascal, with the later being an extension of some sort to UCSD Pascal. The huge success of TP did lead to many other moving toward compatible constructs.
Heck, and then there are languages called Pascal which are derived from already different named languages, like Component Pascal evolved out of Oberon, which itself is a much improved Pascal child.
Bottom line, the distinction when it is a 'new' language or not cannot be made by the name.
Turbo Pascal and its incredible wide spread success (even I was tempted to use it) makes a good maker about how much more successful Pascal was in the 80s than C.
Some languages may be descended from both.
There is no 'pure' linage anywhere in the language world. To some degree all Algol based languages can as well be described as Pascal offsprings.
It may even be necessary to look past the syntactic sugar of brackets vs. keywords to realize that Pascal is mainly data driven, as its big step from Algol was the way to define data structures. In so far Ada makes the most 'pure' child of Pascal anyway (*2). Nowadays a feature to be found across basically all general purpose languages.
But let's try a list of close relatives openly carrying the family tradition:
- UCSD Pascal
- Turbo Pascal
- Concurrent Pascal
- Pascal XL
- Object Pascal
- Pocket Studio
- Vector Pascal (available for the PS2 !)
- MS Pascal
- Compaq Pascal (notable for type casting)
Besides all the variation two lines are notable. One is the Oberon/Modula development driven by Wirth, the other is the Borland Turbo/Delphi line. Each creating their own family of Pascal offspring sharing features. The later creating a linage looking like this:
- (UCSD Pascal)
- Turbo Pascal
- Borland Pascal
- Object Pascal
(I doubt such a claim would still be true today.)
As before, it depends on the way of counting. I'd say Pascal has still an advantage here :))
*1 - It may be noteworthy that Brian Kernighan in contrast offered quite some public (and less than correct) criticism about Pascal.
*2 - All the incompatible Pascal variations where the main reasons for the demand that Ada compilers could only be called that way if they adhere to a strict standard ... which eventually delayed Ada compilers way too long to really inherit the Pascal world, making room for C.