Backporting
Backporting (or porting) is the process of bringing over content from RuneScape, released after the August 2007 Archive, into Old School RuneScape. Currently, the main source of backporting by the Old School team is from a partial backup of RuneScape as it was in May 2012.[1]
Compared to creating new content from scratch, backporting content saves development time and resources by allowing the Old School team to re-use existing assets that were created by prior developers. However, the content is not brought over to Old School as it was in RuneScape; various factors, such as how the content was originally received, as well as balancing changes to fit Old School are taken into account. For example, Nex, one of the most difficult boss fights in 2011, was rebalanced in Old School to accommodate the lack of the Summoning skill, among other changes.
Content from after 2013 is generally unlikely to be backported into the game, as Old School RuneScape takes place in the Fifth Age and the development team has expressed a strong desire to avoid introducing content from the Sixth Age into Old School RuneScape. The death of Guthix will not occur and his Edicts will remain in place, thus keeping Gielinor and Old School in the Fifth Age.[2]