I am building a web-based front end for our VFP-based MRP system for electronics manufacturing.
The original front end and back end were designed very badly, but the database is highly integrated with our business for many years.
New code makes problems with the backend invisible to the user by performing data conversion in real time. The front-end (website) is dramatically better in every possible way.
To be honest I only see this as an intermediate step to completely replace the front end with a website before migrating the back-end to something else. The website only deals in FormData and JSON streams and doesn't need to care what the backend is.