cronosoft is a uk-based non-profit software publishing house established in 2002 by simon ullyatt, which manufactures and markets games and utility software for a range of computers that are considered 'retro' or commercially obsolete. its first release, "egghead in space" (the third egghead game in the series), was written and developed by jonathan cauldwell, and released on cassette format for the sinclair zx spectrum in 2003