Find anagrams of words and "words that can be made with a set of letters" (sort of a sub anagram)
Priority Queue for Elixir. Heap implementation
Sudoku solver in Elixir, which prefers to use heuristics over guessing
XML-RPC encoder/decder for Elixir. Supports all valid datatypes. Input (ie untrusted) is parsed with erlsom against an xml-schema for security.