Dear Working Group members, We now invite you to submit your proposals for the Open Source Working Group session taking place during RIPE 91. From RIPE 91 onwards, all plenary and working group proposals can be submitted through the same system, Pretalx. Please submit your proposals by 25 September 2025. How to submit your talk: 1. Go to the RIPE 91 Call for Presentations page and click on "Submit a topic": https://ripe91.ripe.net/present/call-for-presentations/ . 2. Follow the instructions to set up an account on Pretalx. [1] 3. Important: When filling in the submission form, please pay attention to the dropdown menu under "Track". This is where you select which working group (track) you would like to submit your talk for. In general, each talk is 15-30 mins including Q&A (depending on how much time is needed). If you have some idea and are not sure how/if you should present something, then feel free to contact us as well to discuss the idea! Remote presentations are also possible. As always, we are planning to reserve some time at the end of the WG session for lightning talks. These short (5 to 10 minutes max) updates/talks are decided on the day before the WG session on a time/space available basis. No need to submit to us anything for lightning talks at this time, but you are welcome to do so. [1] Detailed instructions on how to use Pretalx are available here: https://ripe91.ripe.net/present/how-to-submit-a-talk/ Thanks, Marco, Marcos and Sasha, Your Open Source WG Chairs -- ciao, Marco