Download of UCBLogo 6.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app was originally designed by Brian Harvey. We recommend checking the downloaded files with any free antivirus. The application lies within Developer Tools, more precisely IDE. The most popular version among the application users is 6.0.
From the developer:
UCBLogo is a freeware interpreter that I wrote along with several students. (Major contributors are Daniel van Blerkom, Khang Dao, Michael Katz, Douglas Orleans, and Sanford Owings.)
If you think Logo is just a graphics language for little kids, check out a sample program that should impress you.
You may want to check out more software for Mac, such as TopCoder UML Tool, Wcode or JIRA Client, which might be similar to UCBLogo.