Opera (web browser) layout engine of its competitor Google Chrome. Features of the Opera web browser include private browsing, tabbed browsing, download manager, mouse gestures and browser extensions. Opera began in 1994 as a research project at Telenor, the largest Norwegian telecommunications company. In 1995, it branched out into a separate company named Opera Software. Opera was first released publicly in 1996 with version 2.10, which only ran on Microsoft Windows. In an attempt to capitalize on the emerging market for Internet-connected handheld devices, a project to port Opera to mobile device platforms was started in 1998. Opera 4.0, released in 2000, included
Google Sidewiki uncontainable that will need constant monitoring... SideWiki will make it impossible to promote one message and not be held to account." ArsTechnica argued that the comments were of similar value to those on existing sites such as Digg and Reddit, and suggested that without the ability found in Wikipedia to delete and restructure material, it was a "glorified comment system". Google Sidewiki Google Sidewiki was a web annotation tool from Google, launched in September 2009 and discontinued in December 2011. Sidewiki was a browser extension that allowed anyone logged into a Google Account to make and view comments about a