Building a simple proof in LEGO with proof-by-pointing.
The top half of the window displays the proof script. The bottom displays the output from LEGO at each stage of the proof. Here, it shows the current subgoals to be solved. The part of the proof already processed by LEGO has a blue background.
Clicking on terms in the subgoals list generates commands which are added to the proof script.

Coq Proof General running in multiple frame mode, full screen shot (1024x768).
There are separate windows on the screen for the script, goals, and response buffers. In this picture, you can see Proof General's indication that Coq is processing the induction step, because the background of the proof step is pink. It will become blue when Coq finishes that step.

Replaying a domain theory proof in Isabelle's HOLCF logic.
In Isabelle, theory files as well as ML files are coloured. Proof General has some functions for processing and undoing theory files, but most operations it provides are for writing proof scripts in ML files.
Isabelle supports input and output in tokens which display as symbols using the X-Symbol package in conjunction with Proof General. Here you can see some symbols in Isabelle's output.

Replaying a proof in Isar, Isabelle's new proof language developed by Markus Wenzel.

LEGO Proof General running in plain console mode.