Four teenagers have pleaded not guilty at the Old Bailey to the murder of Damilola Taylor.
The boys - one aged 14 and the others aged 16 - also denied assault with intent to rob and manslaughter.
A jury will be sworn in next week and the trial is expected to last three months.
Damilola was attacked in Peckham, south London on November 27, 2000. He bled to death in a stairwell after he was stabbed in the leg.
The defendants are not having to appear in the dock in the Old Bailey's Court 12.
The teenagers, who cannot be named because of their ages, are each sitting at a table with a member of their family and their legal representatives.
Judge Mr Justice Hooper and barristers are not wearing wigs for the trial.
The special arrangements for the trial have been made under the Lord Chief Justice's Recommendations for Trials of Children and Young Persons.
Tables in the courtroom have been arranged in a semicircle around the bench rather than in the normal linear fashion.
Journalists are sitting in what is normally the dock and a media annex has also been set up in the Old Bailey with a live television link to the courtroom.
PA