I am about to use postgres for my website but want to know if it has good multilanguage support before I spend time with it.
We are currently using PostgeSQL on multilingual site and using it's search compatibilities. It's pretty nice in fact. Text search, however required a little bit of configuration.
The fulltext search comes with the same set of builtin dictionaries as on Unix/Linux, which is pretty good coverage. If these cover your needs, you will have the exact same functionality.
If you require custom dictionaries, they also work equally well on Windows, but you are likely going to have a harder time building the installation of them there.
For fulltext search you can use the ispell dictionaries from http://wiki.services.openoffice.org/wiki/Dictionaries
The process of installation them into PostgreSQL is described here (unforunately in ukrainian, but if you are native with Russian or Linux :) you will understand this): http://grandse.org.ua/messages/show/60
http://developer.postgresql.org/pgdocs/postgres/textsearch-dictionaries.html
Here is the common docs for TSearch2: http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/