The McLaren MP4/6 is a Formula One racecar that was designed by Neil Oatley for the 1991 F1 season. It was the first McLaren to be powered by a Honda V12 engine. The car was tested by Gerhard Berger in the off-season, but he was unimpressed with the new engine, feeling it was underpowered for what it was, especially compared to Honda's V10 engine in the previous year's car. When Ayrton Senna returned for pre-season testing, he knuckled down to try to solve the engine's problems. McLaren's domination in the early part of the year was mainly due to the lack of reliability of the Williams FW14.

The MP4/6 had a manual "H" pattern gearbox, with only Ferrari and Williams using semi-automatic gearboxes during 1991.

Senna won the first four races of the season, in the USA, an emotional victory in Brazil, San Marino and Monaco before Williams and Nigel Mansell found their feet with their remarkable FW14 car, which dominated in the mid season. Consistent podium finishes throughout the year helped McLaren, but Senna insisted that Honda step up their engine development programme and demanded further improvements to the car before it was too late. Honda responded with an updated version of the V12 engine, while Oatley redesigned various features of the car, especially the sidepods and wings. Failed electronics and a botched pitstop scuppered Williams' chances in Belgium and Portugal when in the lead allowing McLaren to take their fourth straight constructors' championship and Senna his third and last drivers' championship.

MPEG-4 Part 14 or MP4 (formally ISO/IEC 14496-14:2003) is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital video and digital audio streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. A separate hint track is used to include streaming information in the file. The only official filename extension for MPEG-4 Part 14 files is .mp4.

Some devices advertised as "MP4 Players" are simply MP3 Players that also play AMV video or some other video format, and do not necessarily play the MPEG-4 part 14 format.

MPEG-4 Part 14 is an instance of more general ISO/IEC 14496-12:2004 (MPEG-4 Part 12: ISO base media file format) which is directly based upon QuickTime File Format. MPEG-4 Part 14 is essentially identical to the QuickTime file format, but formally specifies support for Initial Object Descriptors (IOD) and other MPEG features. MPEG-4 Part 14 revises and completely replaces Clause 13 of ISO/IEC 14496-1 (MPEG-4 Part 1: Systems), in which the file format for MPEG-4 content was previously specified.

Ayrton Senna da Silva (pronounced [aˈiɾtõ ˈsenɐ da ˈsiwvɐ] ( listen); 21 March 1960 – 1 May 1994) was a Brazilian racing driver. Senna was a three-time Formula One world champion and is widely regarded as one of the greatest F1 drivers of all time. He died in a crash at Tamburello corner while leading the 1994 San Marino Grand Prix and is the most recent driver to die at the wheel of a Formula One car.

Senna began his motorsport career in karting, moving up to open-wheel racing in 1981, and winning the British Formula 3 championship in 1983. He made his Formula One debut with Toleman-Hart in 1984 before moving to Lotus-Renault the following year and winning six Grands Prix over the next three seasons. In 1988, he joined Frenchman Alain Prost at McLaren-Honda. Between them, they won all but one of the 16 Grands Prix that year and Senna his first World Championship. Prost claimed the championship in 1989, and Senna his second and third championships in 1990 and 1991. In 1992, the Williams-Renault combination began to dominate Formula One. Senna nonetheless managed to finish the 1993 season as runner-up, winning five races and negotiating a move to Williams in 1994.