Rails est un framework web MVC pour le langage Ruby qui connait une certaine popularité en ce moment.
Django est son plus proche équivalent dans le monde Python.
Les deux projets sont issus de projets spécifiques (Basecamp pour Rails, Lawrence Journal World pour Django) et ont été générisés ensuite.
Sam Newman vient d'écrire A comparison of Django with Rails, et conclut sa comparaison assez équilibrée des deux frameworks par:
I said at the start that the two frameworks were developed as a result of two very different applications - and most of the differences between the two are a result of this. If you are developing a simple (in a domain model sense) application where you want to use Ajax to deliver a great UI, Rails is probably for you. If however you want to develop an entire site with different types of applications within it - then Django’s plugable applications and general approach might be what you’re after. Equally, the better user and administration side of Django favours portal style applications – this is something you’ll have to do yourself if you want to use Rails. There is scope for both frameworks to learn from each other, and I still have a question around how well Rails will scale (in terms of the size of the site, not number of hits) - Django has already proved it is capable of this with LjWorld.com. Likewise it will be interesting to see if Django can or even wants to make the use of Ajax as simple as it is with Rails (although work is already progressing along these lines), or if the more powerful language features of Ruby will prove the deciding factor.
Ce qu'il manque à présent, c'est une comparaison avec Zope3...
[Ajouté à 9h44] A lire aussi, une comparaison entre Python et Ruby par Ian Bicking.