What is the X in X-mas?
The result of adding new features to a program or system to the point where the benefit of the new features is outweighed by the extra resources consumed (RAM, disk space or performance) and complexity of use. Software bloat is an instance of Parkinson's Law: resource requirements expand to consume the resources available. Causes of software bloat include second-system effect and creeping featuritis. Commonly cited examples include Unix's "ls(1)" command, the X Window System, BSD, Missed'em-five, OS/2 and any Microsoft product.