I have taken the Forgotten Realms Interactive Atlas, as well as Realm Overseer 3D and City Overseer 3D, and created a web based app to view the contents of all of them. Since it doesn't pre-process any data, you can also open any Campaign Cartographer 2 maps you may have on your system. (CC3 maps technically can render but my site lacks any bitmap symbols, so they will be missing a lot of detail.)
It took me a fair while to actually track down all of the relevant software and data to put this together, in addition to development time. It's not a perfect feature analog to any of the programs, and I may expand it in the future. BetaArchive forum user pond7 ended up being the "hero" of this project by linking me to both of them. I then wrote what I believe to be the first keygen for either program, and uploaded both to archive.org alongside a .reg file to install my generated license files. Prior to obtaining the full software, I actually had been reverse engineering the original demo programs, and an .exe file recovered from one of the update files. This lead to moderate success, but the full software unlocked the entire symbol set, which greatly improved how many maps convert fully.
The site is entirely static, with all parsing/conversion running in C# that's been compiled to WASM, with rendering happening in WebGL. The UI layer is web native, using a small JavaScript layer to communicate with the background app. Initial support for reading .FCW files was based on BC Holmes' CartographerSVG project, though updated to fix a number of fidelity issues and other parsing gaps. To the best of my knowledge, my parsing is identical to the original (excluding minor difference in text placement I haven't bothered to get exactly right).
The UI is inspired by Windows 98, which was the current OS at the time of the original software's publication. It's built with 98.css and this scrollbar style, with my own modifications to keep the theming consistent across all browsers.
You can visit it at https://atlas.kran.gg, please let me know if you encounter any issues, have questions, or any suggestions for things I could implement.