Heartbeat is a full-function high-availability system for Linux and other POSIX-like OSes. It monitors services and restarts them on errors. When managing a cluster (more than 1 machine), it will also monitor the members of the cluster and begin recovery of lost services in less than a second. It runs over serial ports and UDP broadcast/multicast, as well as OpenAIS multicast. It is easily adapted to different interconnect media and protocols. When used in a cluster, it can operate using shared disks, data replication, or no data sharing. Versions starting with 2.0 are comparable to any commercial HA package, providing resource monitoring, larger clusters, and detailed dependency information.
CRM114 is a Controllable Regex Mutilator and Smart Filter, designed for easy creation of filters for things like incoming email redirection, spam filtering, system logs, or monitoring processes. Filtering rules can be either hard-coded (such as regexes), soft-coded (calculated at runtime or read from an external file or process), or learned dynamically by phrase matching (as in Bayesian filtering, Markovian matching, Winnowing, or Hyperspatial classification). This makes it possible to create very accurate filters with very little actual work. Accuracies over 99.9% are achievable.
Check Website is a performance monitoring and uptime notification tool. It will check if a Website is up, and check the response time of the site. The administrator can then choose to receive an email notification if the site is down, or if the site response time is too slow. All results are also written to a daily log file.
Host Grapher is a very simple collection of Perl scripts that provide graphical display of CPU, memory, process, disk, and network information for a system. There are clients for Windows, Linux, FreeBSD, SunOS, AIX and Tru64. No socket will be opened on the client, nor will SNMP be used for obtaining the data.
Mail2sh makes it possible to carry out shell commands by email. Email is sent to a particular user on your host and the commands will be carried out if the user and password given matches ones in /etc/passwd. Commands are executed with the user's privileges, and combined with a PGP module ensures a certain level of security for use. Note that the system is not natively encrypted, so use of an encryption mechanism is highly recommended for security reasons.