Mattermost is an open-source, self-hosted online chat service, with the ability to support both direct messaging and group chats. Its primary function is to offer teams a way to communicate and collaborate in a unified workspace. Modeled to compete with the likes of Slack and Microsoft Teams, Mattermost aims to provide similar functionality while giving users complete control over their data and privacy.

Launched in 2015 by Mattermost Inc., the platform was designed to be extensible and customizable to suit various user needs. One of its strengths lies in the ability to integrate with other popular developer tools such as Jira, Jenkins, GitLab, and many more. This integration capability allows teams to streamline their workflows and improve overall productivity. Mattermost is available in two versions. The Team Edition is the open-source version that includes core features and functionalities. On the other hand, the Enterprise Edition, a commercial version, provides additional features such as advanced user management, enhanced security, and scalability options designed for large organizations.

Let's Encrypt has emerged as a pivotal force in the domain of web hosting and website security. Functioning as a non-profit certificate authority, this organization supplies free SSL/TLS certificates to web servers, empowering website owners to fortify their security practices without bearing any extra expenses. This not only promotes the adoption of robust security measures but also makes secure browsing experiences accessible to a broader audience, ultimately contributing to a safer and more reliable internet for everyone.