Roentgenium is a fork of Nihonium, a bot made for the TBG forums, before it's killed off when the TBGs migrated to Simple Machine Forums.
Like its predecessor, it's currently in early development (especially since it's in the middle of being rewritten), meaning that things, especially the framework, can change at any time. You shouldn't expect something to work the same way it does currently after a month, a few weeks, or even a few days.
If you'd like to know more about what commands it supports, check out the Commands page.
If you'd like to know more about the internal functions, check out the Developer page.