8. A system to interface with multiple social networks, the system comprising: one or more computer processors configured to execute: a scanning module configured to: determine a social networking service that a social networking application is associated with; and locate in the social networking application a custom markup language tag, the custom markup language tag written in a first custom markup language, the custom markup language tag specifying an instruction to implement a particular functionality; a decision module configured to determine that the custom markup language tag should be replaced either with a set of one or more source code commands, or with a second custom markup language tag defined by the social networking service, and written in a second custom markup language, the determination based upon the determined social networking service and one or more criteria, the second custom markup language tag and the set of source code commands both containing instructions, which when executed, implement the particular functionality of the custom markup language tag in the first language; and a replacement module configured to: replace the custom markup language tag in the first custom markup language with the set of source code commands based upon a determination of the decision module that the custom markup language tag should be replaced with the set of source code commands; and replace the custom markup language tag in the first custom markup language with the second custom markup language tag based upon a determination of the decision module that the custom markup language tag should be replaced with the second custom markup language tag.
8. A system to interface with multiple social networks, the system comprising: one or more computer processors configured to execute: a scanning module configured to: determine a social networking service that a social networking application is associated with; and locate in the social networking application a custom markup language tag, the custom markup language tag written in a first custom markup language, the custom markup language tag specifying an instruction to implement a particular functionality; a decision module configured to determine that the custom markup language tag should be replaced either with a set of one or more source code commands, or with a second custom markup language tag defined by the social networking service, and written in a second custom markup language, the determination based upon the determined social networking service and one or more criteria, the second custom markup language tag and the set of source code commands both containing instructions, which when executed, implement the particular functionality of the custom markup language tag in the first language; and a replacement module configured to: replace the custom markup language tag in the first custom markup language with the set of source code commands based upon a determination of the decision module that the custom markup language tag should be replaced with the set of source code commands; and replace the custom markup language tag in the first custom markup language with the second custom markup language tag based upon a determination of the decision module that the custom markup language tag should be replaced with the second custom markup language tag. 10. The system of claim 8 , wherein the decision module configured to determine that the custom markup language tag should be replaced includes determining, from a replacement table, whether one or both of the set of source code commands and the second custom markup language tag are listed as corresponding to the custom markup language tag, and using the correspondence information as one of the criteria, wherein the replacement table comprises: a list of custom markup language tags in the first custom markup language; and for each of the tags in the list, for each supported social networking service, one of corresponding tags in a custom markup language specific to the social networking service and corresponding sets of source code commands.