I would like to use <# #> and <@ @> to delineate preprocessing code and though I'm sure it's possible to avoid conflicts with enough parsing it would be nice to have easy delineation for the following targets:

haxe
c++
c
javascript
python
java
c#
ruby
bash
perl
(l)unix config files
other shells

Do you guys know of any languages or shells that use the strings above in a gratuitous way?