Coming from a Zen background I'll throw in my 2 cents.
Chan is Mahayana Buddhism in China as sprouted from Boddhidharma. Zen us the Japanese pronunciation of Chan. The difference is mainly cultural.
Chan, and thus Zen, have been influenced by Daoism just as it also influenced Daoism. One main Daoist school even teaches it's students to study Chan as well. I find that Daoism and Chan/Zen compliment each other very well.