We did look at Log Parser, and osquery, before starting to build Crab, but neither of them have an exec() command to run programs on query results - such as del

We did look at Log Parser, and osquery, before starting to build Crab, but neither of them have an exec() command to run programs on query results - such as deleting them, unzipping them, or moving them. And Log Parser doesn't support joins either, which are useful to compare the contents of one directory or file with another.