Year-round
Unlike summer and winter of code programs, these initiatives can be repeated at various times of the year or started at any point.
Linux Foundation Mentorship Program
LFX is designed to help developers by providing them with the skills and resources needed to learn, experiment, and contribute effectively to open-source communities. There are various mentorship programs that can be undertaken at various times of the year.
Outreachy
Internship programs in open source and open science intended for underrepresented groups in the tech industry. There are two internship periods: December-March and May-August.
X.Org Endless Vacation of Code (EVoC)
A program very similar to Google Summer of Code but that can be undertaken at any time of the year. Projects typically last 3/4 months and require a nearly full-time commitment.