The latest version of Opera's web browser has shipped with Unite, the company's content-sharing platform.
Unite allows users to turn their Opera browser and computer into the equivalent of a web server, Opera said in its announcement on Monday.
"By giving our devices the ability to serve content, we become equal citizens on the web," said Opera chief executive Jon von Tetzchner. "In an age where we have ceded control of our personal data to third-parties, Opera Unite gives us the freedom to choose how we will share the data that belongs to us."
Unite, which allows people to share content by giving access to specified files, was released at an early stage of development in June.
At the time, security experts criticised passwords being shown in shared URLs, lack of HTTP encryption, and the possibility of unauthorised file-sharing which breaks copyright terms.
Opera said in an FAQ on its site that it was the responsibility of the individual user "to comply with your local laws regarding file-sharing and the different types of licenses that may apply."
While Unite does not encrypt web traffic, Opera said in its statement that the application runs in a "secured sandbox" — users specify which files can be shared.
"You grant access to specified files, such as a directory of data you want to share, without allowing access to anything outside the specified area," said Opera.
Opera fixed the password-sharing issue in its beta version of Unite, launched in October.
The company said in its statement on Monday that if someone knows a My Opera login and password, they can only compromise the pertinent My Opera content.
"They cannot access your Opera Unite applications or the folders you have chosen to share with Opera Unite, nor will they be able to access the rest of your hard disk drive," the company added.
In its statement, Opera invited developers to submit Opera Unite programs in its "battle for the best Opera Unite applications". Opera Unite applications are built using common web standards and Unite APIs. Developers can write Opera Unite applications that use the server facility in the desktop browser to serve content to other Web users.