Websitemaster a.s. is an operator of a service eStránky.cz, which allows internet users to easily develop websites for free within minutes.
The project was officially launched in the Czech Republic at the end of year 2005. In august of 2006 came the acquision of the project by a publishing house Astrosat Media s.r.o..
Astrosat media is a part of the company Astrosat,
which has been a part of the investing group Penta since December 2015. The group includes the publishing house VLTAVA LABE MEDIA a.s., which is the second largest Czech publishing house with its market share of 16.7 % on the Czech market and the largest Slovak publishing house News & Media Holding. VLM publishes Deník - the most read non-tabloid daily newspaper in the Czech Republic and lifestyle publications Glanc, Story, Gurmet, Kondice, National Geographic, bi-monthly magazine Kreativ Praktická žena, traditional publications Týdeník Květy, Vlasta, Překvapení, Magazín Šíp and monthly magazine Dům a zahrada. VLM publishes the highest number of TV magazines such as TV magazín, TV star, TV mini, TV expres and Křížovkářský TV magazín. Since 2015 there are tablet magazines Dotyk, Dotyk Byznys, Dotyk Styl Royal and Dotyk Styl Bydlení, too.