Rudolf Steiner was the founder of anthroposophy, a spiritual philosophy influenced by theosophy and esoteric Christianity. I don't know enough about him or it to comment much yet, but I have found that his writings are largely available online, so for anyone knowing German this can prove interesting esoteric literature:

http://wiki.anthroposophie.net/Rudol..._Gesamtausgabe

The works are numbered GAxyz (GA being an acronym of "Gesamtausgabe" = "Complete works"). I'm for example currently reading GA 103, "Das Johannes-Evangelium." about the Steiner's esoteric interpretation of the apostle John. I see English translations are available, too, so for example here the contents of GA103:

Gospel of John: Lecture I: The Doctrine of the Logos
Gospel of John: Lecture II: Esoteric Christianity
Gospel of John: Lecture III: The Mission of the Earth
Gospel of John: Lecture IV: The Raising of Lazarus
Gospel of John: Lecture V: The Seven Degrees of Initiation
Gospel of John: Lecture VI: The "I AM"
Gospel of John: Lecture VII: The Mystery of Golgotha
Gospel of John: Lecture VIII: Human Evolution in its Relation to the Christ Principle
Gospel of John: Lecture IX: The Prophetical Documents and the Origin of Christianity
Gospel of John: Lecture X: The Effect of the Christ Impulse Within Mankind
Gospel of John: Lecture XI: Christian Initiation
Gospel of John: Lecture XII: The Nature of the Virgin Sophia and of the Holy Spirit
(from: http://www.rsarchive.org/GA/index.php?ga=GA0103)

There's a huge body of writings available, that's for sure. AFAIK Steiner and the anthroposophic branch of the theosophic movement were known for being steeped in esoteric Christianity, and this was part of the schism with theosophy at large that in the opinion of some had a too strong slant towards Eastern teachings. (Though I have to admit that I know not enough about the matter to explain it any better than this.)