Since last November, it was widely believed that the next game would be called S.T.A.L.K.E.R.: Apocalyptic and would utilise the CryEngine2 game engine used in the Crysis series of games rather than the X-ray engine from Shadow of Chernobyl and Clear Sky. However, in an online conference earlier this week, Grigorovitch was asked whether the April 2009 calendar featuring the words 'Call of Pripyat' in Russian was an April Fools' joke. He replied that this was not a joke and would be the name of the second expansion. He added that this new expansion will be released later this year. Furthermore, a full S.T.A.L.K.E.R. title is also in development, although there's currently no information on when we will hear more about this.