[This article was first published on pacha.dev/blog, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't. Because of delays with my scholarship payment, if this post is useful to you I kindly ask a minimal donation on Buy Me a Coffee. It shall be used to continue my Open Source efforts. The full explanation is here: A Personal Message from an Open Source Contributor. If you play the electric guitar, the same scholarship chaos led me to turn my guitar pedals and DIY kits hobby into a business, and you can check those here.Capybara started as an Alpaca clone that uses cpp11armadillo to be is a fast and small footprint software to fit GLMs with k-way fixed effects.The software can estimate GLMs from the Exponential Family and also Negative Binomial models, using a demeaning/centering approach that offers a large speedup for models of a large number of fixed effects.Here is a small benchmark for the following specification using a model from An Advanced Guide to Trade Policy Analysis:where:: exports from country to country at year : Regional Trade Agreement between countries and at time : RTA between countries and at time : dummy variables taking the value of one for international trade for each year , and zero otherwise.: exporter-year, importer-year, and exporter-importer fixed effectsTo obtain the model coefficients I used the following formula with fixed effects:form