Lessons Learned for increasing the accessibility for Right-to-Left Language support in Open Source Community. The default language input for most open-source tools is left-to-right. However, this excludes a huge community that predominantly uses right-to-left (RTL) language and non-Latin scripts such as Arabic, Urdu and Farsi. Right-to-left functionality in many Open Source technologies has long been neglected. This talk will present the lesson we learned in the Open Science Community Saudi Arabia (OSCSA) while localizing Open Source tools (e.g. the Turing Way), introducing new resources, documentation and open educational materials for open source in Arabic. We will present the challenges we went through and the lessons we learned for increasing the accessibility of Open Source tools to RTL users. OSCSA is part of [the International Network of Open Science & Scholarship Communities (INOSC). It is open to individuals from all Arabic-speaking regions without prior knowledge or experience in Open Source. It was built to support inclusive learning communities for novice learners to acquire open-source skills. While growing the community over the last two years, we learned many lessons, which include the know-how for localization of Open Source tools to RTL language. This falls under the internationalization space that is largely overlooked. Localization is especially important in open source projects to support and satisfy the needs of the locales and adapt them to the language and culture of a specific target locale.