LexiLoader (aka ApexDataLoader)
An OSX build of the Apex Data Loader application, quickly export, create or update data in your Salesforce.com organization.
Requires OSX 10.6 or later
Salesforce now have a supported version of the Apex Data Loader for OSX
Now you can download the Apex Data Loader for OSX directly from Salesforce, goto Setup -> Data Management -> Data Loader.
Old Version Downloads
In case you need to run an older version for some reason, you can still download it here.v30 : June 5, 2014 (10.7Mb)
This version is signed with a developerId, so you shouldn't get any warnings from GateKeeper on OSX 10.8 or up.