* Find, download, configure, make, install the "awka" software.  It
  compiles awk to C, and C to .exe.  Learn to use awka and make timing
  comparisons.  Is awka superior to gawk on your examples?

* Write a competitor of "ls" that accepts arbitrary regular
  expressions for selecting file names, as opposed to the limited file
  expansion syntax provided by the shell.  Call this competitor "lr".
  You can implement "lr" as a post-processor of "ls *".