Yet another possible change in Ubuntu’s core components: they’re mulling over replacing GDM with LightDM. Why? Well: “Faster – the greeter doesn’t require an entire GNOME session to run. More flexible – multiple greeters are supported through a well defined interface. This allows Ubuntu derivatives to use the same display manager (e.g. Kubuntu, Lubuntu etc.). Simpler codebase – similar feature set in ~5000 lines of code compared to 50000 in GDM. Supports more usecases – first class support for XDMCP and multihead.”