For the handling and interconnection of the information between the different data bases, is necessary to use a mark language to structure the knowledge in different types from documents, in addition they are possible to be developed for the different types from information of the Web, XML (tensile Markup Language – tensile Language of Marks) it supports the tools of terminological control, is a simple technology that has to his other around complements that it and they much more make and with possibilities majors great. It has a very important paper, since it allows the compatibility between systems to share the information of a safe way, at present trustworthy and easy, it has not been born only for its application in the Web, but one sets out like a standard for the exchange of information structured between different platforms. Greenstone: It is a set of programs and applications of software especially designed for the creation and digital diffusion of collections and documents, which offer a new form to him to organize the information and to publish it in Internet. This tool has been you elaborate as it leaves from the project of Digital Library of New Zealand of the University of Waikato and at the moment is developed and distributed in collaboration with UNESCO and the NGO Human Info. It is a software of low open code available in the terms and conditions of General the Public License of GNU.
KOHA: It was developed in New Zealand to just as the previous one in 1999 by Horowhenua Library Trust and Katipo Communications Ltd. This tool proposes to solve the needs of the information units, several libraries of have proven it to the world with favorable and promising results. It has the potential to become a universal system, as long as a serious interest on the part of the union awakes librarian to use applications of open source.