WebObjects 5.1.4 is
in circulation. It’s an update to provide Mac OS X 10.2 (“Jaguar”) compatibility.
WebObjects is Apple’s Java Server Applications development environment. Using WebObjects, you can build powerful prototypes or deploy a full-scale e-commerce system.
The new version of WebObjects is billed specifically as a developer release; it resolves incompatibilities between WebObjects 5.1.x and Mac OS X 10.2. Apple advised that this update is not required for Mac OS X Server v10.2, however.
It’s also worth noting that the 5.1.4 is, according to Apple, “not cumulative.” That means if you’ve not yet applied either WebObjects 5.1.3 or 5.1.2 to your WebObjects 5.1.x installation, you’ll need to do so before this version can be installed.
The link above will bring you to an Apple KnowledgeBase article where you can get more information about the update. It is available for download through the Software Update system preference pane.