In order to understand the roots of and motivation for let us start with a quote:
"Software producers who maximize their product's potential for useful combination with other software, while at the same time minimizing any restrictions upon its further re-combination, will be the survivors within a software industry that is in the process of reorganizing itself around the network exchange of commodity data."
-- David Stutz – General Program Manager for Shared Source Common Language Infrastructure, Microsoft, 2004.
.NET Core dates back as early as 2001 when Shared Source Common Language Infrastructure (SSCLI) was shared sourced (not for commercial use) under the code name Rotor. This was the ECMA 335, that is, the Common Language Infrastructure (CLI) standard implementation. Rotor could be built on FreeBSD (version...