(There's no video for Mac Dynamic DNS Client 2.0b1 yet. Please contribute to MR and add a video now!)
Dynamic DNS client that uses an extension to always run in the background. Can update multiple DynDNS services at the same time. Obviously, out of the 6 services related to this utility, none are still working as of writing this.
Dynamic-DNS-2.0-beta1-ppc.sit (902.76 KiB / 924.43 KB)
Macintosh Dynamic DNS Client v2.0b1 / compressed w/ Stuffit
Mac OS 8.x - Mac OS 9.2.2
Emulating this? It should run fine under: SheepShaver