The Tree of Life Web Project (ToL) is a collaborative effort of biologists and nature enthusiasts from around the world. On more than 10,000 World Wide Web pages, the project provides information about biodiversity, the characteristics of different groups of organisms, and their evolutionary history (phylogeny).
http://www.tolweb.org/tree/
ClustalW2 is a general purpose multiple sequence alignment program for DNA or proteins. It calculates the best match for the selected sequences, and lines them up so that the identities, similarities and differences can be seen. Evolutionary relationships can be seen via viewing Cladograms or Phylograms.
http://www.ebi.ac.uk/Tools/msa/clustalo/
Entrez is the integrated, text-based search and retrieval system used at the National Center for Biotechnology Information (NCBI) for the major databases related to biotechnology.
http://www.ncbi.nlm.nih.gov/Database/index.html
The Basic Local Alignment Search Tool (BLAST) finds regions of local similarity between gene sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the statistical significance of matches. BLAST can be used to infer functional and evolutionary relationships between sequences as well as help identify members of gene families.
http://blast.ncbi.nlm.nih.gov/Blast.cgi?CMD=Web&PAGE_TYPE=BlastHome