In the wild the Infocenter is used for instance by Tasktop without modification except an additional header…
I like the red style of Wolfram. Even the icons have been adapted:
ARM has made functional changes to the Infocenter. With the menu to the left of the search box you can select where to search, e. g. within the title only or in the whole document. Interestingly, some icons have been removed: there is no Print/Search Topic (and its Subtopics) icon and no Link with Contents icon in the Contents toolbar; no Group by Categories and no number of matches in Search Results.
Sybase also made some search modifications. The drop-down menu right of the search field makes it easier to switch between search scopes that have been created. The flashlight symbol of the search icon to search a topic (and its subtopics) has been replaced with a magnifying glass.
The Infocenter of VMware is hardly recognizable as such. The tabs are shown at the top instead of at the bottom. Maybe because today common web browsers do not have a status line and show the target of a link while hovering it in the left bottom corner which hides bottom tabs.
IBM, the company which has done most of the development work for Eclipse’s Infocenter, added a Collaboration tab to show hot topics and – if logged in – the user’s own comments. There is also a frame below the topic frame for topic-specific comments.
IBM has begun to replace this and other Infocenter instances with its new Knowledge Center. I guess but I don’t know that it is still based on Eclipse Infocenter. It does not use HTML framesets but an iframe for the topic. The search field is wider and the search scope follows automatically the selected book which covers a product.
Most of the modifications described above are about searching. Please drop a comment if you have come across an Infocenter with other modifications. If you like a modification then report it to Eclipse, or even better, implement it and contribute it to Eclipse and watch them reintroduce it into the wild.