If you are attached to a corporate or an enterprise network and connect to internet from behind a BlueCoat proxy which proxies FTP connections then FileZilla FTP client needs needs to be configured accordingly to get it work properly. There is an FTP proxy configuration and a Generic Proxy configuration that can be set in FileZilla client.

Using a Generic Proxy forces it to use Passive Mode connections.However, if you need to use Active mode FTP connections then FTP Proxy should be configured.

Click Edit – Settings from menu to open the FileZilla client settings. Expand FTP in the leftpane and click "FTP Proxy".In the rightpane, select "custom" under "Type of FTP Proxy" and enter the following format specifications:

USER %u@%h

PASS %P

ACCT %w

Once done, enter the IP Address/Hostname and of the Proxy host (if it is not listening on the standard TCP/21 then provide the prot number along with the IP address or hostname, ex: proxy:8085) then the user (username@domainname where domainname is name of the Windows Domain, if it uses WSSO or Intergrated Windows Authentication) and the password (domain password if using windows domain name as above)

This should set the configs appropriately. To check if the connection works OK, try connecting to the external FTP server and you should be able to first connect to the BlueCoat proxy where it first issues a Welcome message as in the following screenshot before it connects you to the remote FTP server.

This should help!

Privoxy is a free Opensource Non-Caching proxy aimed at blocking ADs, Banners, Image Ads and enhance Online privacy. Privoxy is based on Internet Junk Buster and has more enhanced filtering capabilities.

Apart from the main functions of Cookie management, AD/Banner blocking, Privoxy can also has the following special features

Can run as an "intercepting" proxy, which obviates the need to configure browsers individually.

Sophisticated actions and filters for manipulating both server & client headers
 
Integrated browser based configuration and control utility at http://config.privoxy.org/ (or http://p.p/) and can be chained with other proxies. Controllable on a per-site or per-location basis, configuration more powerful and versatile over-all

Web page filtering (text replacements, removes banners based on size, invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)

Modularized configuration that allows for standard settings and user settings to reside in separate files

Support for Perl Compatible Regular Expressions in the configuration files, and a more sophisticated and flexible configuration syntax
 
Improved cookie management features (e.g. session based cookies).

GIF de-animation.

Bypass many click-tracking scripts (avoids script redirection).

Multi-threaded (POSIX and native threads).

User-customizable HTML templates for all proxy-generated pages (e.g. "blocked" page).

Auto-detection and re-reading of config file changes

Privoxy can run on most Linux Unix versions, Solaris, FreeBSD, OpenBSD, MacOS and Windows. For more information, detailed manuals and a solid FAQ, please visit Privoxy homepage here

The latest stable version is 3.0.8 and can be downloaded from Sourceforge here

Internet Junk Buster is a free Opensource Non-Caching proxy for personal use on your PC or server system for company networks or even ISPs. Internet Junk buster is a privacy-enhancing proxy that blocks ads and banners that you wish you never want to see on websites. Blocking these ADs and banners on the website diretly improves the performance on the access to the site.

Internet Junk Buster runs on most of the Linux and Unix systems including Sun Solaris and HP-UX and Windows platforms. There is a seperate installer package available for Windows.

Internet Junk Buster can

Block ADs, Banners, Images and URLs either specific or matching a pattern using a Blockfile. Internet Junk Buster can auto read Block files when it changes without having to restart the proxy itself

Replace blocked ADs banners images etc with a plane image to avoid an ugly look of the site you visit

Control and Block cookies set by the websites on your system.

Replace Cookies with with fake cookies using Wafer options

Selectively allow cookies to be set by specific websites

Enhance Anonimity on the web by censoring what information you divulge on the internet like the Browser info or misrepresent your browser details

Control local hosts that can access through the proxy

The Internet junk Buster can also be configured as a Non-Caching Non-Blocking proxy when required with a minimal change to the configuration.

Once installed, by default, Internet Junk Buster will start and listen on Port 8000. All you then need to do is to change the browsers to use proxy. Most of the known versions of the browsers can work with Internet Junk Buster

For more information, examples, a good FAQ and download for various platforms, please click here for Internet Junk Buster homepage.

WWWOFFLE – World Wide Web Offline Explorer is a free simple easy to configure Webproxy with good security and privacy features. WWWOFFLE is designed to work for Unix and Linux based systems and a partially functional port is available for Windows.

WWWOFFLE can be used for a network with multiple PCs or can be used just on your local PC to improve performance and offline availability of pages.

While WWWOFFLE covers the basic features of a webproxy, there are some special features of WWWOFFLE that is worth mentioning. Especially the Offline access feature specially for Dial-up connections, easy configuration options with a web-interface and the level of control on the caches, index of the caches and security.

Once installed, WWWOFFLE by default listens on the port 8080. There is a detailed list of compatible browser versions here. Worth having a look before implementing the proxy system. Also, the configuration can be fine tuned to the user requirement level.

Some of the highlighting features of WWWOFFLE are

Easy configuration and a built-in web interface for easy configuration and access to cached contents,certifcates for HTTPS etc.

Easy administration with autmated start/stop

Timeout configuration for DNS,Remote Server connections etc to avoid the server crashing

Download control including Pause & Stop for interrupted downloads

Purging old cache and control purging action by maximum cache size, time since last access or last caching

Auto Proxy configuration using Auto-config file

Conditional fetch of pages that have changed based on Expiration Date, Time since last fetch or Once per session

Non-Cached Support for SSL Connections

Caching support for HTTPS connections

Block access to pages and support redirect to alternate pages (like pages educating users on Internet usage policy or redirect to company homepage)

Control pages in cache and backup cache for offline use

Support Compressed pages and Chunked transfer-encoding request from webservers

Dial-on demand for contents not in cache and control websites that can be downloaded the next time system goes online

Offline access fine tune by controlling what can be accessed from cache

Automatic fetching of selected pages and objects from pages and monitoring select pages at regular intervals and recurrsive caching by following links

Insert Footers and modify HTML pages to remove page objects like scripts, javascripts etc

Information on cached pages and the index of the cached pages with multiple indexes for cached pages. Also can search the cached pages using various tools.

Automatic Authentication for external proxies, support pages with username/password for authentication

Censor incoming and outgoing HTTP headers as to what you reveal about your information like browser type etc. This enhances privacy on the internet

For more information, documentation, example scripts to start with and download, click here for WWWOFFLE homepage.

Polipo is a free simple, small and fast caching web proxy. Polipo can be used out of the box and can support a single user on a computer or many computers on a network and can even support higher number of users on a bigger network.

Features of Polipo WebProxy are

Polipo uses HTTP/1.1 pipelining as against Persistent connections if the remote server supports and whether the incoming requests are pipelined or come in simultaneously on multiple connections

Polipo will cache the initial segment of an instance if the download has been interrupted, and, if necessary, complete it later using Accept-Range requests

Polipo will upgrade client requests to HTTP/1.1 even if they come in as HTTP/1.0, and upgrade or downgrade server replies to the client's capabilities (this may involve conversion to or from the HTTP/1.1 chunked encoding)

Polipo fully supports IPv6 (except for scoped (link-local) addresses).

Polipo has primitive filtering capabilities and can be used to ad-filter and be used as privacy-enhancing proxy.
 
Polipo can optionally use a technique known as Poor Man's Multiplexing (a technique that simulates multiplexing by requesting an instance in multiple segments; because the segments are fetched in independent transactions, they can be interleaved with requests for other resources)to reduce latency even further.

Polipo web proxy is supported on most known Linux environments and has packages for Debian,Ubuntu & Gentoo. Users have contributed packages for SuSE, Redhat, CentOS, Fedora, FreeBSD Distributions. For Windows and Mac OS there are installers contributed as well.

Installation is straight forward and is as simple as copying the binaries for Polipi. While in Windows, Installers contributed by users just runs the installation wizard and the default configs are good enough to start working straight away. This is why Polipo can start performing straight out of the box. While customization and restricting websites or localhosts can be performed from config & forbidden files loaded on the system or from the web configuration interface

<IPAddress>:8123/polipo/config

Start Polipo webproxy on your server or pc and it will start listening on port 8123.

Update the proxy address on your browser to use the proxy IP address (localhost for your own PC) and port 8123.

To download Polipo Webproxy, click here

The homepage has good documentation and manuals for installations and advanced configurations.