Islam is sometimes defined as the submission of will to God and typically follows Allah (The God), via the Prophet Muhammad, hence, like Christianity & Judaism, is monotheistic, and also contains many different sects, some of which contain the understanding that Allah is The same God that revealed to Abraham & others, though discount certain other aspects involved with other religious figures.
The main text used is the Koran / Qa'ran, though the Hadith and Sufi texts (depending on the sect/person) are also studied.
Certain sects share with Judaism the Holy Kaba in Mecca and other customs, just as they do with certain sects of Christianity... I personally think one day soon we'll All figure out how to better get along. 🙂