There is no SCRIPT in BitShares. Every functionality has it's own *operation*. A simple transfer operation looks like this:

[0,
                 {'amount': {'amount': 100000, 'asset_id': '1.3.0'},
                  'extensions': [],
                  'fee': {'amount': 264174, 'asset_id': '1.3.0'},
                  'from': '1.2.282',
                  'to': '1.2.880'}]


Multisig is done on a *per-account* basis and not on a *per-address* basis because BitSHares doesn't use addresses. It only knows accounts.

Lots of documentation can be found here: docs.bitshares.eu

How does transaction scripting work in bitshares?  does it use the stack stack approach like bitcoin, or something else?  are loops permitted? Multisig limits? Byte size limits? I can't seem to find documentation for this and was wondering if anyone here was knowledgeable on the subject before I start rifling through the source. 

Thanks