What is better?
A:
server:1080/repo/projectA/trunk/... branches/branch1 branches/branch2 branches/branch3 tags/tag1/... tags/tag2/... server:1080/repo/projectB/trunk/... branches/branch1 branches/branch2 branches/branch3 tags/tag1/... tags/tag2/...
B:
server:1080/repo/trunk/projectA/... branches/projectA/branch1 branches/projectA/branch2 branches/projectA/branch3 tags/projectA/tag1/... tags/projectA/tag2/... server:1080/repo/trunk/projectB/trunk/... branches/projectB/branch1 branches/projectB/branch2 branches/projectB/branch3 tags/projectB/tag1/... tags/projectB/tag2/...
What repository structure do you use and WHY?
The Repository Administration chapter of the SVN book includes a section on Planning Your Repository Organization outlining different strategies and their implication, particularly the implications of the repository layout on branching and merging.