This software offers unrestricted use of portable, public domain libraries at no cost.
Besides the libraries already mentioned, developers can access other useful libraries that are general purpose and biotech-related. These libraries have been developed, maintained, and continuously used in real-life production by hundreds of Web and standalone applications and their programmers (also counted in hundreds).
If you are a C++ developer, you'll find the portable nature of the libraries very useful when building cross-platform applications, even if Bioinformatics isn't your area of specialization. Libraries such as the ones used for CGI/Fast-CGI, HTML, Networking, SQL Database Access, ASN.1, and XML Serialization are quite general purpose and can be used in various applications outside the Bioinformatics problem domain.
The C++ Toolkit undergoes active development with libraries being built every night. The software's source code is freely available through FTP and CVS. The documentation for the C++ Toolkit is also available online in the NCBI Bookshelf format and as a downloadable book in Acrobat's PDF format.