Open source software (OSS) is computer software that has its underlying computer program or ‘source code’ made available under a licence. This can allow other users to adapt and improve it. OSS differs from proprietary software (such as Microsoft Office) which is owned by a company or individual with exclusive rights over it. OSS can have advantages over proprietary software, for example it can prevent ‘lock-in’, or dependence on a single supplier. Government policy aims to create a “level playing field” for Open Source Software, where proprietary and open source alternatives are assessed alongside each other, to ensure the best value for money is achieved. However, many open source suppliers argue that that this does not occur in practice, and that government procurement still favours proprietary solutions. Standards are sets of rules which allow different technologies to communicate with each other. In terms of computer software, compliance with a standard ensures, for example, that a document created in one application can be read in another. Awareness of the concept of Open Standards (where standards are openly available and are not set by a single organisation) is increasing. Advantages of Open Standards include reduced reliance on a single vendor and greater interoperability with other applications.