List of open source debuggers, decompilers,
executable viewers, etc

I have fairly limited understanding of binary formats and the like, but find
the concept of tools to aid reverse engineering fascinating. Tools to
do it well have to do several interesting things, not the least of which
is presenting a huge amount of information in a useful and meaningful
fashion. There is also a certain amount of “magic” in creating something
from nothing (in these cases, source code from bins, or creating symbol
tables from stripped binaries, etc).