[TYPO3-english] Vendor library license in own extension

[Urs Braem]

Hi

I'm setting up a small extension I could later publish to TER if it works out; I need a php-only viewhelper to parse markdown into html.

I wanted to implement
https://github.com/michelf/php-markdown/blob/lib/License.md
but I'm not sure if it's possible due to that non-standard license. Will it "pollute" the Opensourceness that's required for a TYPO3 extension?

Also, there's this alternative using MIT
https://github.com/erusev/parsedown/blob/master/LICENSE.txt
- maybe the better choice, license-wise?