I have a project developed with Symfony2 that almost goes into production. I started with sf 2.8.8 exactly in its standard version, and I have access to the Internet for a very short time, so I do not use composer (it's crazy). So far every time I have needed a bundle (in fact no more than 4) I download it manually, as well as any dependency I have and I break my brain by placing it in the corresponding directories and solving their dependencies. In some cases when they are simple, it has served me, but other times I have had to give up. Right now I need DoctrineMigrationsBundle; I have obtained the package as well as the migrations library, but I do not give with the matter of where it is going. My question is if installing composer (and learning to work with that wonderful tool) does not bother me anything that I have in the project until now. It will not be that by means of composer some error arises by the declaration of some namespace of the bundles configured manually. I repeat, the bundles that I have right now are not at all complex and I even use extensions to doctrine without the bundle.