Heads up, Lifehacker readers and commenters: We've got an awesome new feature we're testing out called text annotation. You've probably seen our image annotation feature, where you can point out ...

In February the W3C approved recommendations to enable annotation on the web. There is a long lineage of annotation tools that enable readers of the web to write comments that overlay content and ...

PDF (Portable Document Format) is one of the most common file formats used to access multimedia content. Today, there are several ways on how to open them through dedicated PDF software. Over the past ...