SPOPS (Simple Perl Object Persistence w/ Security) is a robust and powerful Perl module that allows you to serialize objects. It is unique in that it also allows you to apply security to these objects using a fairly simple but powerful scheme of users and groups. It's also unique in that for most objects, you will not need to write any code. All you need is a fairly simple configuration file, and you can have a class for your object ready to go, right out of thin air.
libfactory++ is a C++ template framework for run-time dynamic type instantiation. You can register single classes or whole hierarchies, and then tell libfactory++ to instantiate objects using the registration key. libfactory++ differs from other factory approaches mainly in its flexibility. First, it can use any constructor a type supports, and allows you to choose (and configure) the constructor to use for each call to create(). Second, it supports custom allocators, allowing you to use, e.g., a memory pool rather than continuous invocations of 'new'.