[$] Python, tail calls, and performance

Ken Jin welcomed EuroPython 2025 attendees to
his talk entitled 'Building a new tail-calling interpreter for Python', but
noted that the title really should be: 'Measuring the performance of
compilers and interpreters is really hard'. Jin's efforts to switch the CPython interpreter to use tail calls,
which can be optimized as regular jumps,
initially seemed to produce an almost miraculous performance improvement.
As his modified title suggests, the actual improvement
was rather smaller; there is still some performance improvement and
there are other benefits from the change.