+* Trace window sizes somehow
+
+* Allow to distinguish between the calls really done by the program, vs the
+ fakes one necessary to retrace correctly.
+
+* Start tracing on demand (e.g., key-press, or by frame no), emitting calls
+ that recreate all current state.
+
+* Add option to include call stack frames in the trace
+
+* Call gzflush() only when there is a signal/exception, except of doing it on
+ every call.
+
+
+Retracing:
+
+* Use visuals that best match those used in the trace; specially auto
+ detect single/double buffer visuals.
+
+* Respect multiple context sharing of the traces.
+
+* Support multiple threads