I can’t claim to be a core developer, but the work I do on MODx is almost always a tremendous amount of fun (it better be, since I don’t get paid for it).
The worst part is hunting down hard-to-find errors, but even that can be fun assuming that you eventually find them. I just spent longer than I care to admit testing the new version of the Formit snippet because I had &smtpUserName as a parameter instead of $smtpUsername.
TBH, one of the most satisfying things for me is just admiring the code that OpenGeek and splittingred have created. I’ve been looking at code for many, many years and Revolution contains, by far, the most elegant production code I’ve ever seen. Bear in mind that Revo contains thousands of files that 99.9% of the time work together perfectly. For someone who appreciates world-class coding, just reading it is like watching an Olympic figure skater.
It’s immensely satisfying to play even a small role in helping to develop and test it. The fact that real-world web developers, without breaking a sweat, will be able to do things with it that have never been done before is just icing on the cake.
Like splittingred, I look forward to seeing what others will do with Revolution. I don’t think most people have any idea yet how powerful Transport Packages and Custom Manager Pages will be down the road. If you look at all the custom apps out there for business and education (e.g. software for class scheduling, college web sites, courseware, auto repair shops, real estate offices, art galleries, RV parks, bridal registries, etc. etc.), all will be doable in Revolution as Transport Packages that will be infinitely easier to build, extend, use, and maintain than the current offerings.