The Garmin Communicator Plug-in no longer works in the Webkit nightlies. This is apparently not recent - the last working stable build for it is r39090 (not working in r39226). The URL provided is the test page for the plug-in: the plug-in does NOT require a Garmin product to be attached for the test to take place. Expected behavior: Garmin plug-in to be detected Actual behavior: Garmin plug-in is not detected I contacted Garmin about this. Customer service response: Thank you for contacting Garmin International. Currently, our MAC Garmin Communicator plugin system requirements entail, Intel-based or PowerPC G3 or later Mac OS 10.4 or later, and Firefox 2.0+ or Safari 2.0+. Webkit is not a supported browser at this time. I am glad you were able to have success with Safari. You may want to get in communication with Webkit, to let them know of this compatibility issue.
<rdar://problem/6525391>
It now works with both vanilla Safari 4.0.2 and Webkit r44481 using Communicator v2.6.4.