Tesla says it's finally releasing 'full self-driving' software after it had to 'rewrite everything'

• Elon Musk said Tuesday that Tesla was releasing a beta version of its long-awaited "full self-driving" software.
• The billionaire said the rollout would be "extremely slow & cautious" but provided little other information about its functionality.
• Tesla's self-driving development has always bucked industry trends, sometimes with disastrous results.

Tesla has begun releasing a beta version of its long-awaited "full self-driving" software, CEO Elon Musk said Wednesday, while providing little clarity about its functionality.

"FSD beta rollout happening tonight," Musk said on Twitter on the eve of Tesla's third-quarter earnings report. "Will be extremely slow & cautious, as it should."

The release, even in a beta version to a limited number of customers, has been years in the making. At a September event, Musk teased the release, saying the update is a "hell of a step change." It could be the final step in his long-promised autonomous coast-to-coast demo that was supposed to happen in 2017.

"We had to rewrite everything," he continued, "labeling software, just the entire code base, it took us quite a while. I call it like 4D in the sense that it's 3 dimensions plus time."

"Full self-driving" has long been an add-on option for Tesla customers as part of its autopilot suite of driver-assistance features, even as both names have taken heat as misleading and potentially dangerous.

Despite Tesla's own warnings for drivers to pay constant attention while using Autopilot, the system's been blamed for a spate of accidents, sometimes fatal, and many a viral video filmed without someone in the driver's seat. All the while, Tesla has flaunted safety norms undertaken by competitors in the field.

"All you will need to do is get in and tell your car where to go," Tesla's website says of full self-driving, a bold claim that no company — not even Tesla — has successfully proven can be done safely.

Nearly ever other self-driving company, from automakers to car startups, have long said their rollout will be slow, measured, and tested. Five companies — Waymo, Cruise, Nuro, Zoox, and AutoX — have received permission in California to test without backup drivers.

Those competitors also notably rely on Lidar, a radar technology with more capabilities than cameras alone. Musk has long shunned Lidar, and called Waymo's technology a "highly specialized solution" compared to Tesla's "general solution" that's "capable of zero intervention drives."

Waymo's John Krafcik hit back subtly, saying "truly autonomous driving machines have warning labels aligned with their capabilities."