title: What is the STL implementation with the lowest memory footprint?
body: <p>I am working on a very large scale computing library that is using STL heavily. The library is being built using MSVC2003 and it is using its STL implementation.
  I am looking for an alternative STL implementation that would help the library lower its memory requirements and increase its performance.</p>
  
  <p>It is not possible to switch to a newer version of MSVC for the moment.</p>
  
  <p>I would like some feedback on real world usage not based on benchmarks if possible.</p>
  
  <p>EDIT: To make it a little clearer, for example some STL implementation (like STLSoft) are proposing specific optimizations for string concatenation; these might sounds small in impact but they can lead to large improvements. STLPort is another good example where they clearly state their goal: having the fastest STL implementation around, there is the stdlib++, etc ... all of these can be good candidates but I have no time to test them all, i require some community help on that.</p>