# open source

An open source mail server Maddy, written entirely in Go language, lightweight and easy to use.

If we want to build a personal email server, RainLoop Webmail is recommended. According to the official website, this is a simple, modern and fast web-based email client.

To deploy an IM system locally, select tinode. In order to facilitate the startup of the backend, we use the WSL environment and install the database with docker to start the IM application.

Free and open source high-performance javascript spreadsheet x-sheet, online excel editor, rich cell styles, rich text, border tilt, merge cells, freeze, undo redo, format brush and other core functions, and also support import and export xlsx files, multiple instances, and support for large amounts of data.