Redmine

I have the same need, and creating a project for the customer and sub-projects for the actual individual projects works fine. You can even get a customer-wide view by looking at information at the customer level. Are you sure this won't satisfy your requirements?

this is just a way i work around at this time - but my problem is one step more difficult:

1. customer
   1. project
      1. backend
      2. frontend
      3. desptop-tools
   2. project
      1. backend
      2. frontend
   3. project - single-website
2. customer
   1. project
      1. backend
      2. frontend
   2. project - single-website
   3. project - Java-Desktop-Tool

actualy i „group” the first level by naming the projects e.g.:

• customer 1 | onlineShop
  • backend
  • frontend
  • frontend-b2b-portal
• customer 1 | portfolio
  • singel-website
• customer 2 | picture agency
  • backend
  • frontend
  • java-upload-manager

I think some of this can be done by using custom fields that will become more useful with the addition of filtering capability at the projects page.

I think something like virtual groups could be helpful for every user not only admins. Every user could customize his project structure and improve his quantity