TidyHQ - Organization management tool to support membership, subscriptions, event planning, and outreach.
jHipster - JHipster is a development platform to quickly generate, develop, & deploy modern web applications & microservice architectures.
Galette - Galette is a membership management web application towards non profit organizations.
Lime Text - Lime Text is an open source text editor.
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Telosys - Telosys is a lightweight Open Source code generator. Telosys allows to generate any kind of language (Java, Python, GoLang, PHP, JavaScript, TypeScript, C#, etc). It works without UML model. All the code generation templates are customizable.