X10

• North American X-10, an unmanned technology demonstrator for advanced missile technologies
• SL X10, a Swedish suburban train
• X10 Wireless Technology, a vendor of home automation products
• X10 industry standard, communication over wired power line or wireless used for home automation
• X-10, a code name for Oak Ridge National Laboratory
• X-10 Graphite Reactor, one of the world's first few nuclear reactors
• Sony Ericsson Xperia X10, a smartphone using the Android operating system
• X10 (video game), a video game by Warthog Games Limited

Computer related

• X10 programming language
• Microsoft X10 Event, a Microsoft conference demonstrating Xbox 360 games/technologies for 2010 on 11th February 2010
• X Window System, 10th protocol version from 1986-1988