An Italian appeals court has overturned the murder conviction of Amanda Knox -- and the judge has ordered her to be released from custody.

Knox burst into tears -- and was immediately rushed out of the courtroom by armed police officers.

Knox's family plans to fly her out of Italy and back into the U.S. as soon as possible.

Cheers rang out inside the courtroom when the ruling was read. Outside the courthouse, the reaction was more mixed -- with people chanting, cheering and booing.

In 2009, Knox was convicted for the 2007 slaying of her former roommate Meredith Kercher. She was also found guilty of falsely accusing her former employer of the killing. But Knox appealed the verdict ... based, in part, on new information related to the DNA evidence in the case.

While the court overturned Knox's murder conviction, it UPHELD her conviction for falsely accusing her former employer of killing Kercher. Knox was sentenced to 3 years behind bars for that crime, but since she has already spent 4 years in custody, Amanda will not serve any additional time.

The court also overturned the murder conviction of Knox's ex-boyfriend Raffaele Sollecito -- who was also ordered to be released from custody.