Since their earlier sightings in June, DIY rockets appear to have become one of the main long-range weapons used by the insurgents. Their significance was reflected in this recent video showing Aleppo Military Council head Col. Abdul Jabbar Aqidi visiting a Syrian opposition rocket factory. Although not manufactured in quite the same volume, DIY mortars have also made an appearance. These weapons have been crucial to providing the Syrian opposition with both direct and indirect explosive firepower.
It's difficult to be certain of how effective and accurate these weapons are. Some videos show occasional accidents (for example, here and here) posted online, demonstrating that these are not the most reliable weapons in the opposition arsenal.