The Chinese DF-11 short-range ballistic missile (also known as the M-11 or, as designated by NATO, CSS-7) was developed as an interchangeable alternative to the SS-1 Scud B, and this solid-fuel missile can be launched from the Soviet MAZ-543 transporter/launcher. It has a range of 280 km, with an 800 kg payload, capable of carrying either an HE warhead or a 90 kiloton nuclear warhead (on the DF-11 version). It has a terminal guidance system similar to the M-9, where the warhead section separates in flight, and a small propulsion system makes minor course corrections in re-entry.
As Grzcyrgba informs me, "DF" stands for dong feng, or "east wind" - a prefix used on almost all larger Chinese missile systems.
Originally shown as part of the M-18 two-stage system in 1987, components of the M-11 (and possibly the M-9) have been sold to Pakistan, in an effort to bypass the MTCR (Missile Technology Control Regime) guidelines. The US then initiated economic sanctions on both countries in 1993. The Chinese sanctions were lifted the following year, although those on Pakistan were held until 1995. Despite denials by both countries, it is widely believed that Pakistan has at least 80 M-11s and 50 launchers, which are believed to be the basis of its Hatf-3 missile program.
A newer model, the DF-11 Mod 2, displayed in 1999, is believed to have a greater range and carry a larger warhead than the Mod 1. It reputedly uses GPS technology to achieve greater accuracy on unsurveyed targets.
Reports indicating that over 100 DF-11s had been deployed on Chinese missile bases opposite Taiwan in 1999 sparked protests from both the US military and the ROC government. The US has since offered to assist Taiwan in developing a missile defense system. The PROC plans on deploying over 500 DF-11s by 2005.
Info taken from www.fas.org, www.rediff.com, www.taiwanheadlines.gov.tw, and www.ucalliance.org.