Fusebox is one of the oldest frameworks for ColdFusion. My first real ColdFusion job was working on a large intranet site built upon Fusebox. The framework has changed hands several times and though it has now gone cold in terms of new development but it is still used by 1 in 3 ColdFusion developers according to the State of the CF Union survey results from 2014.
Party like it's 1999
There's a lot of legacy code out there still running on FuseBox, but that doesn't mean it has to stay that way. The Internet has moved on to design patterns like MVC and more-object oriented approaches for code reuse and testing. The thought of reworking your old codebase might seem scary, especially if you're not familiar with MVC and you aren't using any OO principles. Don't despair though, it's often times better to make incremental improvements to code instead of trying to throw it out and rewrite it from scratch. The old adage says, how do you eat an elephant? "One bite at a time!"