`_` definitely clashes with IPython and Jupyter's use of it.

However, if you import it from Ibis then it ceases to be used as "most recent result" and remains the ibis underscore object (unless of course you explicitly assign it to something else).

Regarding backend compatibility, there are definitely a few kinds of things that we don't currently abstract over. One is regular expression syntax and another is floating point math (e.g., various algebraic properties that are violated that result in slightly different outputs).

Hope you give it a go, and please report issues at https://github.com/ibis-project/ibis.