Here are some of the notes I took while reading the book: When you run an Xcode project from a standard (i.e., non-admin) user, you might be asked to enter credentials of a user in the “Developer Tools group.” You can fix this by adding the (current) user to the group: When you purchase something from the Mac App Store, you’ll see a little icon in your dock, but that doesn’t show you the percentage of progress.
The icon is small, and the progress bar seems to remain blank for a long time for bigger downloads.
If you try something similar with the computer (try leaving the semi-colon off in C or miss an indent in Python, for example), you’ll get a nasty error message.
This book your computer to work with the looser languages used by humans (like English) instead of the stricter counterparts used by machines.
Disclaimer: I received this book for free through the O’Reilly Blogger program. is a very short “book” on RFID (Radio Frequency Identification), a way to tag and identify objects over varying ranges, and how to use Arduino to create a few interesting RFID projects.