Apple kicked off its Worldwide Developers Conference on Monday with the usual keynote led by Tim Cook. First on the agenda was a look at the new version of OS X. It’s called Yosemite, keeping in line with its new tradition of California-based names, which was launched by last year’s Mavericks.

This was demoed by Apple’s Craig Federighi, who joked at the name “Weed” was also considered. This got a lot of laughs from the crowd.

There are some subtle design tweaks. “You wouldn’t believe how much time we spent crafting a trash can,” said Federighi.

The dock looks slightly different. “Goregeous,” as I believe Federighi put it.

It has refined toolbars, window materials and window constructions. There’s a new “dark mode,” which got a lot of applause. This lets users use darker toolbars. The changes extend throughout applications. There’s a new look for sidebar apps, and some new notification center features, including a look at Calendar, reminders, weather, etc. You can also add content from other widgets and apps you’ve downloaded fro the App Store.

Spotlight has a new interface. You can click on the magnifying glass, and get a big search field right in the middle of the display, and quickly get to apps, documents, etc. It also taps into the Internet to get you Wikipedia info, maps, etc.

Calendar has a new Day view. Safari and Mail are also getting some new features, and there’s a new iCloud Drive.

A new feature of the OS is Continuity. AirDrop works between iOS and Mac now. A feature called “hand-off” enables devices that are around each other to utilize things you are working on, so you can easily switch. For example, you can compose an email on your phone, and your Mac will prompt you on the doc, so you can finish working on the message on the Mac.

Instant Hotspot sees your phone and automatically sets up a hotspot so you can get on the network. Even if your phone is across the room “sitting in a handbag.”

SMS messages from people with other types of devices will now show up on Mac. They can do the same thing with phone calls. When you receive a phone call, your Mac gives you caller ID. You can accept the call and use your Mac “as a speaker phone”. This works if your phone is across the house on a charger. You can also dial from the Mac in Contacts. Even from a webpage, if you see a number, you can call it from your Mac.

In the demo, Craig called Dr. Dre, who welcomed him to Apple with a lot of applause. Dre thanked the audience for creating apps. Unfortunately, no “Deez nuts” jokes.

According to Cook, Macs grew by 12% over the last fiscal year, compared to a 5% industry decline. The mac installed base has reached 80 million, and over 40 million copies of Mavericks have been installed since its October release. That’s the biggest single release in the company’s history.

Cook couldn’t resist the opportunity to compare Mavericks use to Windows 8. Over 50% of the Mac install base is working on Mavericks (the latest version). That’s the fastest adoption of any PC operating system in history, according to Cook, who pointed out that Windows 8 was at 14%.

“Need I say more?” Cook asked.

Yosemite is available to developers today. Everyone else will get it in the fall. It will be free. There’s a public beta program for non-developers at apple.com/osx/preview.

Image via Apple