Hello everyone, My name is Alberto Flores, I am an student from Mexico, I've been part of the #guix IRC channel as 'happy_gnu' and 'Blackbeard'. I've used Guix for a few years, both as a package manager and distribution. I want to apply to Google Summer of Code. The ideas I am most interested are a) for GNU Guix: 'Content-addressed protocol for substitutes' and b) for GNU Shepherd:  "Syntax and semantics of systemd units in the Shepherd", because I have a feeling any of this two would improve the experience of most Guix users. However, I would like to ask for feedback in which might be a better option, I would like to chose a project that I can get help and the community is interested in. Any help with the project and proposal would be much appreciated. I am open for other ideas too. I know Christopher Webber started a thread about Guile based build-tool and it looks great, but it seems like a huge project for me and I would not like to fail in case I were accepted. On other notes, I'll be sending my first patch this weekend, I packaged the game widelands and it works, hopefully it will be accepted. I also plan to send patches to the manual, and participate as much as I can. Thank you all for your feedback and comments. Alberto