Some Linux filesystems support storing additional meta data called extended attributes against files, directories and links. This Tcl extension wraps the syscall interface to allow Tcl programs to manipulate the extended attributes.
DualFS is a next-generation journaling file system which separates data and meta-data on different devices (usually, two partitions on the same disk or different disks), and manages them separately.
EBML, or Extensible Binary Meta-Language, is a simple XML like binary language for describing data in structured style. EBML was originally designed for use in the Matroska project, but the developers saw that EBML was very flexible and extensible.
MacOsX Finder like browser for UN*Xes with Win* like Control Panel function. Requires firefox (due to XUL support) and SQLite for meta data search (similar to spotlight)