MSIDIFF is freeware to compare or disassemble Windows Installer databases (a "MSI to TEXT" utility). While it is a command line based tool, the installer creates shell extensions so that the decompile operations can be invoked by right clicking on a file in Explorer. The output is very easy to read and can be processed by my MAKEMSI tool or can be further processed via my PPWIZARD preprocessor.
Advanced Bash Scripting Guide 3.7 - Complete ebook tutorial and reference on shell scripting with Bash in Linux/UNIX/BSD. This is the equivalent of a 672-page printed book.