concurrent__ (which is my main goal), I've been exploring the possibility of
making the mark phase recursive instead of iterative (as it currently is).
-__ http://llucax.com.ar/blog/blog/post/-4c9dd5b5
+__ https://llucax.com.ar/blog/blog/post/-4c9dd5b5
__ http://www.digitalmars.com/d/
__ http://en.wikipedia.org/wiki/Garbage_collection_%28computer_science%29
__ http://www.memorymanagement.org/glossary/c.html#concurrent.garbage.collection