Remark:
"Deep" links to specific web pages may become obsolete as the sites are being updated. 
Please report bad links to Tino Hochepied

Find a mutant mouse

• International mouse strain resource (IMSR) 
  (http://www.informatics.jax.org/imsr/index.jsp)

Find mutated ES cells

• International gene trap consortium (IGTC)
  (http://www.genetrap.org)
• Resource on mouse mutagenesis, phenotypes and complex traits
  (http://www.informatics.jax.org/mgihome/other/phenoallele_commun_resource.shtml)
• IKMC targeting repository https://www.mousephenotype.org/imits/targ_rep

Companies that generate mutant mice 

• GenOway (http://www.genoway.com)
• inGenious (http://www.genetargeting.com)
• OZgene (http://www.ozgene.com)
• Polygene (http://www.polygene.ch)