Free client machines software for linux

Visual Turing Machine project is a program that lets you create Turing machines with a point and click interface instead of using esoteric languages.
You can pack your complex machines into small boxes, and then reuse them as part of a bigger machine. VTM also features an infinite length tape.
Enhancements:
- New features include an n-ary set of symbols, multiple windows (MDI), a huge workspace (10000x10000 pixels) without a memory issue, the ability to edit your own machines, the ability to execute machines n times (where n is undefined), the ability to use expressions (like n+5) to execute machines, the ability to execute machines at desired speeds, statistics to see how many instructions were executed and how much tape was "used", and an easy wasy to translate the program to other languages.

Check Your Network Address Translator for Compatibility with Peer-to-Peer Protocols.
If you are accessing the Internet from behind a Network Address Translator (NAT) of some kind, I would appreciate your help in surveying the behavior of different NATs, in terms of how and whether they support a certain technique for enabling peer-to-peer communication between NATted hosts (particularly when both endpoints are behind NATs). Down, you can understand what NAT is.
Suppose there are three communicating hosts: A, B, and C. Host A is a "well-known" Internet server with a permanent IP address, which acts as an "introducer" for the other two nodes. (For example, Host A might be a well-known ultrapeer or a game catalog server of some kind.) Host B, using Host As "introduction" services, would like to establish a direct peer-to-peer connection with host C. Both B and C, however, are behind (probably different) network address/port translators, and neither of them has exclusive use of any public IP address.
To initiate a peer-to-peer connection with host C, host B first sends A a message requesting an "introduction" to host C. A sends B a reply message containing Cs IP address and UDP port number as reported by host C, in addition to Cs IP address and UDP port number as observed by A. (If C is behind a NAT, then these two address/port combinations will be different.) At the same time, host A sends host C a message containing Bs IP address and UDP port numbers - again, both the ones reported by B and the ones observed by A, which will be different if B is behind a NAT.
Now B and C each know that they want to initiate a connection with each other, and they know each others public (NATted) as well as original IP addresses and UDP port numbers. Both B and C now start attempting to send UDP messages directly to each other, at each of the available addresses. If B and C happen to be behind the same NAT, then they will be able to communicate with each other directly using their "originally reported" IP addresses and UDP port numbers.
In the more common case where B and C are behind different NATs, the "originally reported" addresses will be useless because they will both be private IP addresses in different addressing domains. Instead, the IP address/UDP port combinations observed by A can be used in this case to establish direct communication. Although Bs NAT will initially filter out any UDP packets arriving from Cs public (NATted) UDP port directed at Bs public port, the first UDP message B sends to C will cause Bs NAT to open up a new UDP session keyed on Cs public port, allowing future incoming traffic from C to pass through the NAT to B. Similarly, the first few messages from B to C may be filtered out by Cs NAT, but will be able to start passing through the firewall as soon as Cs first message to B causes Cs NAT to open up a new session. In this way, each NAT is tricked into thinking that its respective internal host is the "initiator" of this new session, when in fact the session is fully symmetrical and was initiated (with As help) simultaneously in each direction.
Required NAT Behavior
There is one important requirement that the NATs must satisfy in order for this technique to work: the NATs must be designed so that they assign only one (public IP address, public UDP port) pair to each (internal IP address, internal UDP port) combination, rather than allocating and assigning a new public UDP port for each new UDP session. Recall that a "session" in Internet terminology is defined by the IP addresses and port numbers of both communicating endpoints, so host Bs communication with host A is considered to be one session while host Bs communication with host C is a different session. If Bs NAT, for example, assigns one public UDP port for Bs communication with A, and then assigns B a different public UDP port for the new session B tries to open up with C, then the above technique for peer-to-peer communication will not work because Cs messages to B will be directed to the wrong UDP port.
RFC 3022 explicitly allows and suggests that NATs behave in the former, "desirable" fashion, by maintaining a single (public IP, public port) mapping for a given (internal IP, internal port) combination independent of the number of active sessions involving this mapping. This behavior is not only good for compatibility with UDP applications, but it also helps to conserve the NATs scarce pool of public port numbers. Maintaining a consistent public port mapping does not adversely affect security in any way, either, because incoming traffic can still be filtered on a per-session basis regardless of how addresses are translated. There in fact appears to be no good reason not to implement the desirable behavior in a NAT, except perhaps for the implementation simplicity of naively allocating a new public port for every new session. Unfortunately, RFC 3022 does not require NATs to implement the desirable behavior, which has led me to wonder just how many real NATs actually do, and hence this page.
What NAT Check Does
The program natcheck.c is basically just a program that "pings" a well-known UDP port at two different servers that are publically accessible on the Internet. Both of these servers run the program natserver.c, with the command-line arguments "1" and "2" respectively. In addition, there a third "conspiring" server runs natserver with the command-line argument "3". Whenever each of the first two servers receives a UDP request, it not only sends a reply directly to the sender of that request, but also sends a message to the third server, which in turn "bounces" the reply back to the original client. The effect is that the client will receive not only solicited "ping" replies from the server the request was directed to, but also "unsolicited" replies from the third server.
To determine if the network address translator in use is implementing the desirable behavior of maintaining a single (public IP address, public port) mapping for a given (client IP address, client port), the client program natcheck.c basically just initiates a sequence of simultaneous pings to the first two servers (in case some of the requests or replies are lost in transit) and checks that the clients address and UDP port as reported by both servers is the same. If the NAT naively allocates a new public port for each new session, then the source port as reported by the two servers will be different, and its time to upgrade your NAT.
The replies echoed from the third server are used only to check whether the NAT properly filters out unsolicited incoming traffic on a per-session basis. Since the client never sends any messages to the third server, if the NAT is properly implementing firewall functionality, the client should never see the third servers echoed replies even after opening up active communication sessions with the first two servers.
Enhancements:
- The NAT Check client no longer attempts to guess whether you have Basic NAT or Network Address/Port Translation (NAPT). It turns to be quite difficult to test for this property reliably, because many NAPTs attempt to bind a private UDP port to a public port with the same port number if that port number is available, causing NAT Check to falsely report Basic NAT. The only way to test for this property reliably would be to run NAT Check on at least two client machines simultaneously, and since this property isnt terribly important to P2P apps its just not worth the trouble.
- The NAT Check client now tests for one additional NAT feature, which I call loopback translation. If a NAT supports loopback translation, it means that a host on the private network behind the NAT can communicate with other hosts on the same private network using public (translated) port bindings assigned by the NAT. Most NATs probably do not support this feature yet, but it may become increasingly important in the future where P2P clients may be located behind a common ISP-deployed NAT as well as individual home NATs. More details on loopback translation will appear in the next version of my Internet-Draft, to be released soon.
- The NAT Check client program now has a command-line option, "-v", which turns on verbose messages during the test.

Virtual Machine Manager (virt-manager for short package name) is a desktop application for managing virtual machines. It presents a summary view of running domains and their live performance & resource utilization statistics.

A detailed view presents graphs showing performance & utilization over time. Ultimately it will allow creation of new domains, and configuration & adjustment of a domains resource allocation & virtual hardware. Finally an embedded VNC client viewer presents a full graphical console to the guest domain.

The application logic is written in Python, while the UI is constructed with Glade and GTK+, based on mockups provided by UI interaction designers. The libvirt Python bindings are used to interacting with the underlying hypervisor.

This enables the application to be written independant of any particular hypervisor technology, although Xen is the current primary platform. When libvirt is ported to additional hypervisors minimal effort will be required to update the management UI.

CVTSA is a suite of tools for GNU/Linux that allows users to administrate computers via web or email wherever they are, using browsers or email clients [via computer or mobile] and without running daemons[opening ports] on their own computer.
WEBCVTSA is a tool that allows users to administrate their computers [running GNU/Linux] using a form on a web page to post commands.
It has lots of interesting features:
It works as a shell but it receives commands via web.
NO DAEMON RUNNING ON YOUR MACHINE [webcvtsa is only a client], no ports opened to control your computer!
CREATE DYNAMICAL REVERSE SSH TUNNELS TO DIRECTLY CONTROL YOUR SYSTEM
ERASE MAYBE DANGEROUS/ILLEGAL FILES ON YOUR MACHINE WHEREVER YOU ARE [you can use also mobiles !]
BLOWFISH ENCRYPTION OF COMMANDS
CVTSA-EMAIL allows users to administrate their computer via email.
NO DAEMON RUNNING ON YOUR MACHINE [webcvtsa is only a client], no ports opened to control your computer!
CREATE DYNAMICAL REVERSE SSH TUNNELS TO DIRECTLY CONTROL YOUR SYSTEM
ERASE MAYBE DANGEROUS/ILLEGAL FILES ON YOUR MACHINE WHEREVER YOU ARE [you can use also mobiles !]
It works as a shell but it receives commands via email.
Emails could be sent from a computer mobiles [GRPS, WAP, UMTS].
once readed.
It recognizes true emails so attackers cannot run commands.
Enhancements:
- webcvtsa-0.0.8
- src/email.c: support for sending confirm email once executed command.
- README: updated

Oracle client is a simplistic Perl-based Oracle client that tries to mimic some of the functionality of PostgreSQL and MySQLs text-based SQL clients.

It is relatively simplistic, but much more useful than dbishell or sqlplus.

The project supports readline, history, desc, and various shorthand commands like d, , c, etc.

Perl MUD Client project is a text-based MUD client supporting SSL, ANSI, telnet negotations, and MCP.

PMC is a text based mudclient written in Perl 5. It utilizes GNU readline, supports SSL, local editing support through MCP (MudClientProtocol), full telnet negotiation support and of course ANSI support if your terminal supports it.

Unlike other mudclients with input line editors/history, it also supports the telnet character mode, which enables it to use e.g. fullscreen applications within a mud (like the xeditor found on some LP Muds).