This is a link to a dramaturgical website authored by my friend, Dr. Ren Powell, a fellow Aggie Player who is now a theatre teacher/poet/translator/published author in Norway.  Her website is in Norwegian, but there's an English button right at the top that will translate the site for you. It covers playwrights and movements after 1875.  Her first language is actually English, but the translation is automatically generated and is a little wonky.  She spent a year compiling and vetting these sources for her course.
This is a link to Ren's website where you can read about her poetry, plays, projects, translations, and her blog, as well as a bio.