strange discharge coming from tree

[eddie26]

hello everyone,

 

i was wondering if anybody would be able to pinpoint exactly what is happening to this tree. there seems to be some kind of weird discharge coming from it. its sappy in nature, but im sure it is not normal. the affected area is really nasty looking, as you can see in the photo. there are other trees of the same type located in the vicinity, however this is the only one afflicted with whatever this is. about half of the tree's foliage is dead (not shown in picture). as far as i know its been like this for as long as ive lived here (5 years). im curious to know what exactly this is. i couldn't tell you what kind of tree it is though. sorry!