Need the Opensource License Agreement

I need the Open Source License Agreement for Ubuntu Mate. I’m unable to find the same in website. Can someone help me on this please?

You mean the website?? The website is there https://creativecommons.org/licenses/by-sa/4.0/

The text…

https://creativecommons.org/licenses/by-sa/4.0/legalcode

As Ubuntu MATE is an official flavour of Ubuntu, it inherits the same licensing:

Ubuntu is a collection of thousands of computer programs and documents created by a range of individuals, teams and companies.

Each of these programs may come under a different licence.

Most software (including the MATE Desktop) is licensed under the GPL.

As @malwaredpc points out, other areas like artwork and the website itself, is under CC SA-4.0.

You can type in a pseudo terminal

man gpl

and a version of GPL 2.0 will appear.