Changed third second-level heading '##Choosing the right tool for the job' to '##Choosing your development tools'. Attempted to smooth out the two introductory paragraphs, trying to make them more clear and inviting. Tried to make the introduction more accurately reflect what is discussed in the chapter. Removed short descriptions of Portlets and OpenSocial Gadgets since their longer descriptions (third level headings) immediately followed them.  Added any information from the shorter descriptions that was not included in the longer descriptions. Other general edits were made to improve sentence structure and clarity.