At WWDC 2015 Apple announced that it was letting the public test the upcoming new version of the Mac operating system - OS X El Capitain - as part of its new, free beta program. Here's how to sign up to Apple's OS X Beta Seed Program.

The program will let you download and run beta versions of OS X 10.11, there will be multiple versions as Apple irons out the bugs and glitches. Those who register for the OS X Beta Seed Program can download the software, and begin giving feedback to Apple to help the company perfect the update before it's released to the public in the autumn.

The public are able to sign up to the program now - just visit Apple's website here. Apple will send an email to those who sign up for the beta to inform when the El Capitan Beta is ready for download. Last year those who had signed up for the beta program received an email from Apple around 24 July.

In 2014 the email included a redemption code for downloading the beta.

Last year's programme was the first time Apple has ever opened a Beta Seed Program. The company did release a Public Beta of OS X in 2000, but those who wanted to download it had to pay $30 for the privilege.

Registered Apple Developers are able to download pre-release versions of most of Apple's software too, but it costs $99 per year to register as a developer.

You can read all about the new version of OS X here and here are our top ten features coming in OS X El Capitan

Plus: Find out how to download and prepare for OS X El Capitan

The risks of Apple's OS X Beta Seed Program

It's worth noting that participating in Apple's OS X Beta Seed Program is not a light undertaking, so you should consider whether it's really right for you before downloading and installing the pre-release software. After all, being pre-release software, it's bound to have bugs and issues that could cause things to go spectacularly wrong with your Mac, which isn't helped by the fact that Apple is not obligated to provide any support for pre-release software.

If you only have one Mac, and you're intending to run the pre-release software on that machine, you might want to reconsider. Apple suggests that you should run the pre-release software on a dedicated Mac, not a Mac that you use for business or production purposes.

There's also the important matter of privacy. By agreeing to test the OS X beta software, you're essentially giving Apple permission to collect diagnostic, technical and usage data from you, unless you go through the process of opting out.

Last year the first beta version of OS X 10.10 Yosemite came with several known issues, including problems in Safari while trying to access Netflix content, iPhoto, Photo Stream and iCloud Photo Sharing problems, iCloud Drive issues and AirDrop issues, so beware.

See also: Safely install the Mac OS X beta by dual-booting.

If you're still interested in signing up to the OS X Beta Seed Program, here's what you'll need to do.

How to sign up to the OS X El Capitan Beta Seed Program

First, you'll need to go to the OS X Beta Seed Program website. From there, you can find out more about the program by clicking Learn More or FAQ.

You must be aged 18 or older with a valid Apple ID, and you'll also need to be willing to accept the Confidentiality Agreement, which means you agree not to share information or screenshots of the update.

By clicking 'Join Now' and then 'Get Started' on the OS X Beta Seed Program website, you'll be taken to the 'Sign In' page. If you don't already have an Apple ID, you can create one by clicking 'create one now' in the grey box on the left. If you do have one, however, you can go ahead and sign in using the password you normally use for your iTunes and other Apple services.

Next, you'll be taken to the OS X Beta Seed and Confidentiality Agreement. You'll need to read the agreement (you can view it as a PDF if you prefer by clicking the link beneath the scroll link) and then click accept. Unless of course you don't agree with the terms in which case you'll want to stop the registration process now.

Also: Will your Mac run the new OS X? Check the requirements here.

How to get your Mac ready for El Capitan beta updates

Apple gives clear instructions about how to prepare for the install on the Enroll your Mac page.

First Apple advises users to make a backup of their data and files before installing any beta versions of OS X, stating: "Always back up your data and files before installing beta versions of OS X. If you have multiple Macs, we recommend installing OS X Yosemite Beta on your secondary computer. Backing up files on a Mac is easy with Time Machine, the built-in backup utility in OS X."  You can find out how to use Time Machine to back up your Mac here.

Once you've backed up, you can download the Beta Access Utility here (OSXPublicBetaAccessUtility.dmg). You'll need to have OS X Yosemite installed and have 2GB or more of memory with 8GB or more of available space. Once downloaded, open the disk image, then double-click the package to run the installer and enroll your Mac for public beta updates. Note, there may not be any public beta software available at time of install.

Click the blue 'Download Beta Access Utility' button to download the utility (currently called Yosemite Beta Access Utility), and then click on package that has been downloaded onto your Mac to install it. The app will take up 826KB of space on your Mac. It can be installed on your Mac - no need to install it on a separate partition, this is just the means by which you will download the beta.

Once installed the app will launch the Mac App Store, which will show you if any updates are available (currently there is a pubic beta for OS X Yosemite 10.10.4). Any updates that have not yet been released to the public and are therefore part of the OS X Beta Seed Program will be labelled 'Pre-release'.

You can click update to install those pre-release versions of software. Just need to click Update to install the most current version of the OS X Public Beta.

With each new release, the latest OS X Public Beta will automatically appear in the Mac App Store and you’ll receive a Notification when it is available.

How to provide feedback to Apple through the OS X Beta Seed Program

Now that you've signed up to the OS X Beta Seed Program and have installed the OS X beta, you'll be able to provide feedback to Apple about bugs and other issues that need to be fixed.

You'll find the Feedback Assistant in your Dock (it's a purple circle with a speech bubble within it, as shown above). Click it and then sign in with your Apple ID to begin providing feedback to Apple using the form that the Feedback Assistant provides.