O'Reilly are offering a series of 50% off of PDFs of
- HTML & XHTML: The Definitive Guide, 6th Edition http://shop.oreilly.com/product/9780596527327.do
- RESTful Web Services http://shop.oreilly.com/product/9780596529260.do

O'Reilly are offering a series of 50% off of PDFs of

I let a tool I liked sit dead for a year rather than build the features I wanted. An MCP server meant I never had to, and your customers can do the same to your product.
du -sh for the quick answer, ncdu for the cleanup, df for the disk itself: every command for checking directory size in Linux, plus why du and df never agree.
One :%s command replaces every match in a file before a find dialog would even open. The Vim substitute patterns worth the muscle memory: flags, ranges, capture groups, and multi-file edits.
Your existing team is buried in the complexity of your existing product. AI rewards the team with a blank slate. Most companies don't have one.