I am a machine learning enthusiast, check out my text classification API here uclassify.com. I am pretty happy with the implementation of my own translation algorithm
If you are into number sequences, my hobby project sequencedb.net might interest you, it's a database of procedurally generated integer and decimal sequences.
Games are also fun to program you can see some of my creations at playchilla.com. I've published the source code for a b-spline noise thingy. Professionally I've worked on DICE (2006-2008), King (2009-2011) and Mojang (2012-currently).
J. Maiga, 2018, Euler Phi, Chowla and Mersenne primes
J. Maiga, 2018, Efficient computation of ratios between divisor sums
J. Maiga, 2018, Liouville's function and triangular numbers
J. Maiga, 2018, Proof of formula for upper s-Wuthoff sequence
J. Maiga, 2018, Stack sorting and fertility numbers
J. Maiga, 2018, Fun with signed nested exponentials and the prime numbers
J. Kagstrom, 2005, Improving naive bayesian spam filtering
My twitter handle is @jonkagstrom