This question is a duplicate of this feature request.
We have a lot of good answers here on AskUbuntu, but as time goes by, they get outdated. How about allowing members with enough reputation to flag a question or answers as needing update, so that either the author or someone else can update the it by making changes so that it will work in the present.
Either the OP can update it, or we can start a update queue from which members with higher reputation can take up flagged posts and update it to the current context for a small reward in reputation points.
If the number of update requests start become overwhelming, we can increase the number of flags required for considering the update request valid. Also if the system is implemented, as time goes by, the number of requests will come down as more older posts get updated.
In this way, we can maintain the answers/questions and they will remain relevant for more period of time.