Annap,
OLGA's main site is closed. However, if you CLICK HERE you will get the olga.net home page. On the left is a link entitled "Search Engine". If you go there, you are welcome to search to your heart's content. If you get a "hit" for your search there will be a list of States (California, Florida, etc.) and countries (Poland, Germany, etc.) that have "mirror sites" of OLGA. If you click on them, it takes you to the tablature you have found. By the way, those "foreign" sites are English language capable.
Don't ask me to explain the legalisms here ('cause I don't understand). Suffice it to say OLGA is alive, just not well. But, like Alice's Restaurant you can nearly "get anything you want" (you just can't sit at the table, you have to "take out").
Roger in Baltimore