A recent message from Patrik made me wonder how many languages do have
formal syntax that can be potentially described in a formal grammar
(YACC/EBNF/PEG). The search in Frathwiki returned almost nothing.

Of course, not all conlangers are programmers so I don't think presenting a
working syntactic parser should be a requirement for accepting that a
language has formal syntax.

I wish there was a list of such languages. I'd like to study them more
since as of now I know only two of them:

1. Loglan
2. Lojban

Can you add more?
It'd be nice to have a list of such conlangs.