AZ.pl was founded in 1996 in Stettin, Poland. In 2010, the majority of AZ.pl was taken over by Key-Systems. The company is has the third largest registration of Polish domains, with more than 10% of the market and over 240,000 domains. The company offers a large variety of services such as domain name registration, email accounts and site-building tools.
AZ.pl is the first ICANN accredited registrar in Poland and as of 2010 it ranked as the third most prominent registrars of the Polish .pl ccTLD, with 10% of the market. At that time it was administering some 240,000 domains.
For a comparative breakdown of the extension that their customers are registering with AZ.pl, see here.