6. Adobe Flash: Dead IT Skill Walking
Adobe's Flash technology may still be widely used, but it's soon going to be overshadowed by HTML5, an open standard for creating dynamic Web content that doesn't have the same security baggage as Flash. As Global Knowledge points out, Adobe dropped support of the mobile platform Flash back in 2011.
While Flash is not supported among major mobile operating systems, HTML5 is supported on most desktop operating systems, along with iOS, Android, Mac, Windows and Linux. Global Knowledge’s point: HTML5 will soon replace Flash, so start brushing up on your HTML5 coding chops.