Free traversal software for linux

Gibraltar Firewall is a firewall and router package, based on Debian/GNU Linux, which perfectly meets all individual requirements for a state-of-the-art firewall.
Independent of the kind of Internet connection (dedicated line, ADSL, dial-up connection), Gibraltar provides for secure connections. So you can turn to something more important without ruffle and worries - your job!
Gibraltar is free for private use. The private license is restricted to a maximum of 5 concurrent connections and includes the easy-to-use webinterface. For obtaining a private license, please contact us via email.
Attention: Without a valid license file, Gibraltar will not run properly!
For the private use of Gibraltar, no claim on support or guarantee can be raised.
All ISO images are copyright of Rene Mayrhofer and eSYS Information Systems GmbH, but may be copied and distributed freely. Several components of Gibraltar are under GPL or BSD license. For detailed usage licenses read the packet documentations under /usr/share/doc on the ISO image.
If you would like to distribute Gibraltar commercially, please refer to our partner program.
Gibraltar can be completely configured with the web-based configuration tool GibADMIN. The configuration of Gibraltar occurs over an encoded, secured connection, and can be done with any browser. The web-interface is designed intuitional and concise, and enables the administrator to change the configuration very easy and quick.
Gibraltar convinces through jutting flexibility and extensive functionality.
Main features:
- SYSTEM
- Live CD technology: Gibraltar boots and runs fully off CD-ROM
- No hard disk installation required
- Specially hardened Linux kernel
- Languages: English, German, Finnish
- Remote configuration with web interface (SSL 128 Bit) or remote login (SSH)
- Easy configuration management
- Automatic live updates: interval can be configured
- NETWORK SUPPORT
- Ethernet: 10/100/1000 MBit/s: static or DHCP, virtual IP addresses
- ADSL Ethernet modems: PPP over Ethernet, PPTP
- ADSL USB modems: PPP over ATM
- Modem dial in: serial, USB
- Unlimited number of network interfaces
- STATEFUL PACKET INSPECTION
- Protocol support: ICMP, TCP, UDP, GRE, ESP, AH, IPv4-over-IPv6
- Flexible packet filter: interface, MAC address, IP address, service, port,....
- NAT: Network address translation: dynamic and static
- PAT: Port address translation: load balancing (Round Robin)
- Free definition of aliases and groups: addresses and ports
- DoS/flood - protection: predefined, expandable
- Randomized IP sequencing
- Selective TTL manipulation
- Protocol pass through: PPTP, FTP, H.323, IRC
- VPN (VIRTUAL PRIVATE NETWORKS)
- VPN IPSec gateway
- VPN PPTP server: MPPE 128 Bit data encryption
- Network-to-network VPN
- Network-to-client VPN: compatible with Microsoft Windows 2000 / XP
- Unlimited number of VPN tunnels
- Authentication with PSK (Private shared key) and X.509 certificates
- Encryption: 3DES, Blowfish, Twofish, AES, CAST, Serpent
- Authentication PPTP: CHAP, MS-CHAPv1, MS-CHAPv2
- NAT traversal
- Perfect forward secrecy (PFS)
- DEEP PACKET INSPECTION
- Secure SMTP relay: incoming, outgoing, attachment blocking, block lists, antivirus and spam protection
- Transparent HTTP proxy: no client configuration necessary, spam protection
- User authentication: user list, active directory integration, LDAP
- Content caching
- Content scanning: antivirus, cookies, active X, java script
- FTP proxy: transparent outgoing, incoming
- Transparent POP3 proxy: antivirus, spam protection and protection of dangerous attachments
- ADDITIONAL SERVICES
- Dynamic DNS
- DHCP server
- Secure DNS resolve
- SSL wrapper for arbitrary services
- Portscan detection
- Antispam filter: rule based, Bayes, RBL, Razor and DCC
- ClamAV virus scanner
- OPTIONAL: Kaspersky virus scanner

OSSP defines an abstract data type of a data buffer that can assemble, move and truncate chunks of data in a stream but avoids actual copying.
It was built to deal efficiently with communication streams between software modules. It especially provides flexible semantical data attribution through by-chunk labeling.
It also has convenient chunk traversal methods and optional OSSP ex based exception handling.
Enhancements:
- An Autoconf check is provided for the va_copy(d,s) macro.
- The build environment was upgraded to GNU autoconf 2.59, GNU libtool 1.5.20, and GNU shtool 2.0.3.

Openswan is an implementation of IPsec for the Linux operating system.
It provides IPSEC (IP Security, which is both encryption and authentication) kernel extensions and an IKE (Internet Key Exchange, keying and encrypted routing daemon), as well as various rc scripts and documentation.
It is known to interoperate with other IPSEC and IKE systems already deployed by other vendors such as OpenBSD, Cisco, and CheckPoint. It features Opportunistic Encryption, subnet extrusion, X.509 certificates, NAT Traversal support, XAUTH, and DNSSEC support.
Enhancements:
- Compile fixes for 2.6.16-2.6.18-rc2, a dpdaction=restart fix, and various miscellaneous fixes for ipcomp, nat-t, and rekeys.

RhinoRider provides applets with an interface to the Web document. Depending on the capabilities of the browser, RhinoRider project aims to provide these DOM features:
- Core level 3
- XML
- Events
- Traversal
- Range

Tree::Binary::Search is a binary search tree for Perl.

SYNOPSIS

use Tree::Binary::Search;

my $btree = Tree::Binary::Search->new();

$btree->useNumericComparison();

$btree->insert(5 => "Five");
$btree->insert(2 => "Two");
$btree->insert(1 => "One");
$btree->insert(3 => "Three");
$btree->insert(4 => "Four");
$btree->insert(9 => "Nine");
$btree->insert(8 => "Eight");
$btree->insert(6 => "Six");
$btree->insert(7 => "Seven");

# this creates the following tree:
#
# +-------(5)----------+
# | |
# +-(2)-+ +-(9)
# | | |
# (1) (3)-+ +----(8)
# | |
# (4) (6)-+
# |
# (7)
#

$btree->exists(7); # return true

$btree->update(7 => "Seven (updated)");

$btree->select(9); # return Nine

$btree->min_key(); # returns 1

$btree->min(); # returns One

$btree->max_key(); # return 9

$btree->max(); # return Nine

$btree->delete(5);

# this results in the following tree:
#
# +-------(6)-------+
# | |
# +-(2)-+ +-(9)
# | | |
# (1) (3)-+ +-(8)
# | |
# (4) (7)
#

This module implements a binary search tree, which is a specialized usage of a binary tree. The basic principle is that all elements to the left are less than the root, all elements to the right are greater than the root. This reduces the search time for elements in the tree, by halving the number of nodes that need to be searched each time a node is examined.

Binary search trees are a very well understood data-structure and there is a wealth of information on the web about them.

Trees are a naturally recursive data-structure, and therefore, tend to lend themselves well to recursive traversal functions. I however, have chosen to implement the tree traversal in this module without using recursive subroutines. This is partially a performance descision, even though perl can handle theoreticaly unlimited recursion, subroutine calls to have some overhead. My algorithm is still recursive, I have just chosen to keep it within a single subroutine.

Rhinohide is a Java implementation of the W3C DOM, layered over a Web browsers native JavaScript.
Rhinohide provides an interface for applets to manipulate their containing Web pages, using a standard Java binding of the DOM. The code is still in alpha, and coverage is incomplete, but at least partial support is provided for these DOM features:
- Core level 3
- XML
- Events
- Traversal
- Range

Template::Manual::Views is a template toolkit views (experimental).

This section describes dynamic views: a powerful but experimental new feature in version 2.01 of the Template Toolkit.

A view is effectively a collection of templates and/or variable definitions which can be passed around as a self-contained unit. This then represents a particular interface or presentation style for other objects or items of data.

You can use views to implement custom "skins" for an application or content set. You can use them to help simplify the presentation of common objects or data types. You can even use then to automate the presentation of complex data structures such as that generated in an XML::DOM tree or similar. You let an iterator do the walking, and the view does the talking (or in this case, the presenting). Voila - you have view independant, structure shy traversal using templates.

In general, views can be used in a number of different ways to achieve several different things. They elegantly solve some problems which were otherwise difficult or complicated, and make easy some things that were previously hard.

At the moment, theyre still very experimental. The directive syntax and underlying API are likely to change quite considerably over the next version or two. Please be very wary about building your multi-million dollar e-commerce solutions based around this feature.