Redshift is a group of educational planetarium and astronomy software packages that allow the user to observe the sky from a range of dates, print off data based on the observations and (in some versions) control a telescope. It uses data from the Hubble Guide Star Catalog II. Began in the early 1990s, the current version is 7.0 (released in 2009) which includes 3D models of the galaxy, multimedia tours and access to star catalogs. Platforms include Windows (7/Vista/XP), Mac, iPhone and iPad, PC editions include Premium (with a library of 100 million objects and telescope control) and Compact (fewer objects in the library, no telescope interface). All version support Redshift-Live links - an online site to share observation information and other astronomy pictures and data.