The work of biochemists and molecular biologists often is dependent or extremely favored by a preliminary computer analysis. Thus, the development of an efficient and friendly computational tool is very important. In this work, we developed a package of programs in Javascript language which can be used online or locally. The programs depend exclusively of Web browsers and are compatible with Internet Explorer, Opera, Mozilla Firefox and Google Chrome. With the EBiAn package it is can perform the main analysis and manipulation of DNA, RNA, proteins and peptides sequences. The programs can be freely accessed and adapted or modified to generate new programs.Universidade Estadual Paulista Júlio de Mesquita Filho, Departamento de Bioquímica e Tecnologia Química, Instituto de Química de Araraquara, Araraquara, Rua Professor Francisco Degni, nº 55, Quitandinha, CEP 14800-900, SP, BrasilUniversidade Estadual Paulista Júlio de Mesquita Filho, Departamento de Bioquímica e Tecnologia Química, Instituto de Química de Araraquara, Araraquara, Rua Professor Francisco Degni, nº 55, Quitandinha, CEP 14800-900, SP, BrasilInstitute of Chemistry, UNESP - Univ Estadual Paulista, Department of Biochemistry and Technological Chemistry, Araraquara, São Paulo, Brazil.