pst-exp
Outlook PST File format experimentation
Articles about MS-PST file format:
MS-PST - How to Navigate the Node BTree http://blogs.msdn.com/b/openspecification/archive/2010/11/30/ms-pst-how-to-navigate-the-node-btree.aspx
MS-PST - The Relationship Between Nodes and Blocks http://blogs.msdn.com/b/openspecification/archive/2011/02/11/ms-pst-the-relationship-between-nodes-and-blocks.aspx
MS-PST - How to decode data pages using Permutative Decoding. http://blogs.msdn.com/b/openspecification/archive/2012/02/08/ms-pst-how-to-decode-data-pages-using-permutative-decoding.aspx
MS-PST - Parsing a Heap-on-Node Property Context Block http://blogs.msdn.com/b/openspecification/archive/2014/05/30/ms-pst-parsing-a-heap-on-node-property-context-block.aspx