The C++ Portable Types Library (PTypes) is a simple alternative to the STL that includes multithreading and networking. It defines dynamic strings, character sets, variants, lists and other basic data types along with threads, synchronization primitives and IP sockets. It is portable across modern Unix and Windows systems and includes a sample HTTP daemon showing the full power of the library.
Hoard is a scalable memory allocator (malloc replacement) for multithreaded applications. Hoard can dramatically improve your application's performance on multicore machines. No changes to your source are necessary; just link it in. Hoard scales linearly up to at least 64 processors. Supported platforms include Linux, Solaris, Mac OS X, and Windows.
The libstatgrab library provides an easy-to-use interface for accessing system statistics and information. Available statistics include CPU, Load, Memory, Swap, Disk I/O, and Network I/O. It was developed to work on Linux, FreeBSD, and Solaris. The package also includes two tools: saidar provides a curses-based interface for viewing live system statistics, and statgrab is a sysctl-like interface to the statistics.
DISLIN is a high-level, easy-to-use plotting library for displaying data as curves, bar graphs, pie charts, 3D-colour plots, surfaces, contours, and maps. Several output formats are supported, such as X11, VGA, PostScript, PDF, CGM, HPGL, TIFF, and PNG. Plotting extensions for the interpreter-based languages Perl, Python, and Java are also supported for most operating systems.
The GNOME Structured File Library is a utility library for reading and writing structured file formats. Support for MS OLE2 streams is complete, as is zip import. There is also support for document metadata and some initial work on decompressing VBA streams in OLE files for future conversion to other languages. This library replaces libole2 and is used in gnumeric, mrproject, abiword, libwv2, koffice. It is also part of the AAF format.
The POCO C++ Libraries are a collection of class libraries for developing network-centric, portable applications in C++. The classes integrate perfectly with the C++ Standard Library and cover functionality like threads, thread synchronization, filesystem access, streams, shared libraries and class loading, sockets and network protocols (HTTP, FTP, SMTP, etc.), including an HTTP server, as well as an XML parser with SAX2 and DOM interfaces and SQL database access.