overview query languages

Hi,
I´m currently working on my master thesis about a "topic grid" (distributed
topic maps). As I´m new to topic maps, I´m not familiar with all parts of
it. I´m wondering at the moment about the current status of the various
standards around topic maps (HyTM, XTM, SAM and soon) and especially a
standard for a query language (TQML). Thats why some questions, I would be
happy getting some answers to:
- what is the timeframe for TMQL to get published, so that there will be
implementations which support the specification?
- as querying topic maps is a main part of the topic grid, I want to give an
overwiew of currently available query lanuages. What do you think about the
most important languages: tolog, astma, empolis, toma, tmpath? Except for
tolog, I couldn´t find implementations of the languages which are available
either freely or as open source. Did I miss something or is this right?
- I had a look at tm4j. AFAK, tm4j supports tolog as query languages. Is
this right? Are there any restrictions or limitations of tolog support in
tm4j?

Sorry, partly the questions don´t directly refer to TMQL, but I think this
is the best "meeting place" for all the guys that are touch with query
languages for topic maps.
Regards,
Stefan