Effectively, Jaish al-Islam
...Liwa al-Islam (Brigade of Islam) was established by Zahran Alloush, the son of Saudi-based religious scholar Abdullah Mohammed Alloush, after Syrian authorities released him from prison in mid-2011 where he had been serving time for his Salafist activism. The group claimed responsibility for carrying out the July 2012 Damascus bombing that killed Defense Minister Dawoud Rajiha, Deputy Defense Minister Asef Shawkat, and Assistant Vice President Hassan Turkmani. It was a driving force behind actions in the Damascus region. It cooperated and conducted joint operations with al-Nusra. In Sptember 2013 Saudi Arabia engineered Liwa al-Islam's merger with fifty other more or less Salafist groups as a counterweight to al-Nusra, which the Learned Elders of Islam considered was growing too powereful...and the Free Syrian Army
... the more palatable version of the Syrian insurgency, heavily influenced by the Moslem Brüderbund...
(FSA) affiliated Ahmad al-Abdo brigade have lost control of Jabal Zubaydi, Tall Daba'a and Jabal al-Afa'i.
Rebel factions and the Syrian Arab Army (SAA) are still on good terms in the eastern Qalamoun, a somewhat rare scenario in other Syrian regions still affected by more than 5 years of war.
Previously, the SAA has provided air support against ISIS in favor of Jaish al-Islam and the Ahmad al-Abdo brigade. In turn, rebel commanders have vowed not to harass nearby SAA forces.