They used to be the norm in Django, Flask, RoR and ASP.NET, which made up the majority of the non-PHP web. These days database queries are cheap enough that mos

They used to be the norm in Django, Flask, RoR and ASP.NET, which made up the majority of the non-PHP web. These days database queries are cheap enough that most new sites just use session tokens, but that's also not something you can modify (well, besides transplanting it from a different session).