In August 1995, Microsoft entered the web browser space with Internet Explorer. At the time, it was based on the same browser technology everyone was using - Spyglass. After the browser took off, the company put more resources than 6 team members behind it and made it an integral part of the Windows operating system. While that move brought on the famous antitrust investigations across the globe, it also led to Internet Explorer owning the web for years.
When Google introduced Chrome, that began to change - Microsoft began to lose market share and the joke of Internet Explorer only being used to install Chrome became the norm. With Windows 10, Microsoft took a new direction with its browser development, mostly retiring Explorer and moving to Edge. Since then, Edge has changed its own direction, abandoning the Edge rendering system and taking on the Chromium renderer.
Now, all of Microsoft's browser ambitions are finding a single path going forward. Internet Explorer 11, which was released in 2013 and was the last major version, is coming to an end for Microsoft's own products. They will stop officially supporting the operating system in Teams November 30, 2020, and the rest of the Microsoft 365 suite will lose support on August 17, 2021. Microsoft said,
Customers will have a degraded experience or will be unable to connect to Microsoft 365 apps and services on IE 11. For degraded experiences, new Microsoft 365 features will not be available or certain features may cease to work when accessing the app or service via IE 11.
While web product support is ending for Internet Explorer, the browser is not going away. It continues to exist to ensure older corporate web projects can continue to operate for companies that rely on them. However, while product support is ending within Internet Explorer, Edge Legacy, which is the pre-Chromium version, will see the end of all support on March 9, 2021. This is in line with the announcement that modern Edge, the Chromium version, will be automatically installed as part of Windows Update, and will be a permanent replacement for Legacy Edge.