i've done a couple things, huh?
my first celeste mod was AltSidesHelper, which allowed adding extra side-levels (called alt-sides) with more flexibility and control than vanilla allowed. this is where i learned C# and the C# modding tools; ASH includes a lot of small modifications throughout the game, and while i still want to redo much of it, i'd say it's fairly impressive for a first mod & fairly clean for what it is.
i also have a personal "helper" mod, prismatic helper, which i update over time with new mechanics for anyone to use. maybe i'm biased, but i think some of them are pretty damn cool: simplified cutscenes that don't require programming knowledge, levels-in-levels, and smaller things like "doors with multiple locks" as i need them
there's a lot more i had planned to put into it, but nowadays i tend to bundle code with specific maps, and split things up more finely, since it reduces the maintenance load significantly. sometimes i'll make it public later, like the tile layout anchor originally created for SSC3, but otherwise it's on a request basis
speaking of requests, i've done a lot of little things for collaborative projects over time, including SSC3, FLP, and contributions to communal helper
oh, and i also work on this little map editor project called snowberry, check it out sometime
i set up the opus magnum mod loader, quintessential, inspired by & using tools from the celeste mod loader, alongside my own custom deobfuscation tool. to make that easier to use, i began on a GUI mod installer, though it remains unfinished
i also made the first content mod for it, unstable elements, and the first utility mod zoom tool
in the leadup to the bot-making contest, i made a java library for reading and manipulating OM puzzle & solution files, called omnivore, which later become my first published package
have you ever heard of this little game called "minecraft"? yeah it's pretty cool
MC modding is where i learned to program, so naturally i have an unending pile of unfinished projects there. most of them i don't really have anymore either, so... they're not getting mentions. just imagine i listed like 15 one-item mods.
in fact, i'd say i've only ever finished two. automotons has you building and programming robots called automotons, using items as simple instructions & with an ingame guidebook to help you. i'm still pretty proud of the design!
i also made an addon for thaumcraft 6 called planar artifice; a mod for a mod, it was a pretty random bundle of new features that i thought were cool really, but some of those involved messing with TC6 itself and doing things i haven't seen elsewhere. after almost losing the code, i put it on github and made is free-to-use, and someone else picked it up and ran with the ideas. i'm not sure where they ran to exactly
my best work has probably been in arcana, an unfinished spiritual successor to thaumcraft. it's development has gone through many, many, many... hoops, but i'm very happy with its current state, and intend to finish it sometime. (i mean, it's playable now! just ignore the bugs)
i'm a big fan of programming language design, and a while back i tried my hoof at making one myself: cyclic, which was largely based on java, with an increasing number of incremental changes (and entirely separate compiler/tools). i never ended up getting to "the point" of the language; at some point i started rewriting it entirely to facilitate the metaprogramming i wanted to implement, but never finished, sigh
but a compiler alone does not a language make! i also made an intellij plugin and gradle plugin for it, allowing you to write cyclic code in IJ & compile it with gradle, and even have a fairly pleasant experience! turns out that implementing incredibly minor IDE features for your language can be incredibly satisfying too
(also means i'm no longer scared of the gradle demons - you have no power over me anymore!)
i've helped out with the IJ MCdev plugin and the IJ ANTLR plugin, adding features that i felt were sorely missing ("copy access widener" fix my beloved). i also helped out with everest; while i'd like to do more there, it's a living interconnected spaghetti project that requires much more time and planning to change.
also, i spent a while working on the vineflower java decompiler, particularly on decompiling pattern matching & formulating the plugin system
i made a crate for implementing garbage collection in rust called swifer, which i then published. funnily enough, this was a while before i ever published a java project.
i have various other tiny things lying around, like an interactive demonstration of principal component analysis to help with my revision - it's a pretty fun language for prototyping imo