May - August rounds of Outreachy internships are run in parallel with the Google Summer of Code program to encourage more people from underrepresented backgrounds to apply to both. If you are a student applying for a coding project, you most likely are eligible to apply for the Google Summer of Code program, and should consider applying for both programs.
Note that Google Summer of Code and Outreachy stipends differ. The Google Summer of Code stipend varies across countries based on Purchasing Power Parity. The Outreachy stipend is a flat amount of $5,500. For applicants in most countries, the Outreachy stipend is higher than the Google Summer of Code stipend.
Outreachy has a significantly
smaller funding pool than Google Summer of Code, and we accept less interns than Google Summer of Code. In order to maximize the number of people who have a Free and Open Source Software internship, we encourage communities to accept applicants for Google Summer of Code where possible. The final decision on who to accept for each program is up to each participating community.
If you apply for both Outreachy and Google Summer of Code, you will first be considered for Google Summer of Code. You will typically only be considered for Outreachy if the community that wants to accept you for Outreachy has dedicated funding for all interns it wants to accept.
We understand that participating in Google Summer of Code instead of Outreachy in some countries means getting a smaller stipend. However, it's worth noting that Google Summer of Code is a prestigious program. Participating in it gives you the same type of experience as Outreachy (and likely the same wonderful mentor). You will be paid the same amount of money as your peers in your country, and your opportunities, including your earning opportunities, will be the same upon completing either program.
It's up to you to decide whether you would accept a lower stipend from Google Summer of Code in order to increase your chances of being accepted by applying to both Google Summer of Code and Outreachy. If you would only be able to participate if you were accepted for Outreachy, you don't have to apply for Google Summer of Code.
If the community you are interested in is participating in both programs, the mentor you are working with for Outreachy will typically be able to mentor you for either program, though you should check with them about it. You should work on and complete applications for both Outreachy and Google Summer of Code, which typically have similar questions.
If you qualify for Google Summer of Code, you can consider all communities participating in it, not just the ones participating in Outreachy. Check individual community pages for their Google Summer of Code idea lists, advice on getting started, and application requirements. As with Outreachy, the best way to prepare to apply for Google Summer of Code is to start contributing early to the community that interests you.
Unlike Google Summer of Code, Outreachy is open to non-students and non-coders, so you should only apply for Outreachy internship if you are either not a student or not a coder.