Where is example ajax code?

A total n00b question, I know. But, I want to look at the example tabs code and cannot find the php files that are referenced in the ajax directory. For example, in the tabs example "content via ajax", line 29 has href = "ajax/content1.html" but the referenced code is never shown in the "view source" link.

Are the complete examples (including the subdirectories) available for download as a bundle?

Thanks,