Chiron FS is a FUSE based filesystem that implements replication at the filesystem level like RAID 1 does at the device level. The replicated filesystem may be of any kind you want; the only requisite is that you mount it. There is no need for special configuration files; the setup is as simple as one mount command (or one line in fstab).
xlike is a patch collection for the Linux vanilla kernel. It includes as many stable enhancements for the Linux kernel as possible. These include code from Xen, Kernel Mode Linux, Rule Set Based Access Control, Novell AppArmor, Openswan, grsecurity, Linux VServer, Linux-PHC, web100, Nefilters, Suspend2, Speakup, SquashFS, UnionFS, Bootsplash, BadRAM, and more. It also contains many drivers and fixes.
weta-dfs is a distributed file system. It is designed to be fail-safe through replications of files, fast and easy to install, platform independent, and to have fast recovery from crashes. It consists of Data Node Servers and one Meta Data Server and a java.io.File-like client API.
Kerrighed is a Single System Image operating system (SSI) for clusters. It offers the view of a unique SMP machine on top of a cluster of standard PCs. The goals are high performance of applications, high availability of the cluster, efficient resource management, high customizability of the operating system, and ease of use. It is implemented as an extension to Linux operating system (a set of Linux modules and a small patch to the kernel).
v9fs provides a Plan 9 9P2000 resource sharing protocol for the Linux 2.6 kernel. This can be used to share files, devices, /proc, /sys, etc. It also works with Plan 9 file servers, and can be used to mount synthetic file systems from Plan 9 applications (see the plan9port project).
translucency is a loadable kernel module for Linux that virtually merges two directories, making it possible to overwrite files on read-only media and compile projects (such as the Linux kernel) with different options without copying sources each time. No user-space tools have to be changed. The process is also known as inheriting (ifs), stacking, translucency (tfs), loopback (lofs), and overlay (ovlfs).
openMosix is a a set of extensions to the standard Linux kernel allowing you to build a cluster of out of off-the-shelf PC hardware. openMosix scales perfectly up to thousands of nodes. You do not need to modify your applications to benefit from your cluster (unlike PVM, MPI, Linda, etc.). Processes in openMosix migrate transparently between nodes and the cluster will always auto-balance.