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Viscosity For Mac & Windows: Version 1.4.8
Wednesday, April 9, 2014

Version 1.4.8 of Viscosity for both Mac and Windows is now available! This version addresses the recent OpenSSL "Heartbleed" security vulnerability, and all users are strongly advised to update to this release as soon as possible.

The OpenSSL "Heartbleed" bug is a very serious vulnerability in versions 1.0.1 to 1.0.1f of OpenSSL. OpenSSL is OpenVPN's default library for providing encryption services and hence OpenVPN users are exposed to this flaw. While it is more difficult for an attacker to target an OpenVPN client than a server, it could still potentially allow an attacker to obtain session keys and decrypted data and so it should be treated seriously. Version 1.0.1g of OpenSSL fixes this flaw and this is the version included with Viscosity 1.4.8.

For more information regarding the OpenSSL "Heartbleed" bug please visit The Heartbleed Bug website. For further information on how this bug can affect OpenVPN users please visit the OpenVPN Community Wiki Page.

Version 1.4.8 Mac Release Notes:

  • Resolves issue where HTTP Proxy credentials may fail to save to Keychain
  • Adds option for automatic HTTP Proxy authentication
  • OpenSSL updated to version 1.0.1g (resolves "Heartbleed" bug)
  • Various bug fixes and enhancements

Version 1.4.8 Windows Release Notes:

  • Adds option for automatic HTTP Proxy authentication
  • OpenSSL updated to version 1.0.1g (resolves "Heartbleed" bug)
  • Localization updates
  • Various bug fixes and enhancements

The 1.4.8 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 11:36 PM

Viscosity For Mac & Windows: Version 1.4.7
Thursday, December 19, 2013

We're pleased to announce that version 1.4.7 of Viscosity for both Mac and Windows is now available! We've vastly improved retina display support for Mac users, and high-DPI interface support for Windows users. We've also created some sleek new toolbar icons for Viscosity's Preferences window that make Viscosity look even better on both standard and retina level displays.

Version 1.4.7 Mac Release Notes:

  • Interface improvements for retina displays
  • New toolbar icons
  • Resolves issue where auto-disabling DHCP could fail
  • Various bug fixes and enhancements

Version 1.4.7 Windows Release Notes:

  • Windows 8.1 support improvements
  • New toolbar icons
  • Improved user Interface for high DPI users
  • Localization fixes and improvements
  • Russian Localization updated (thanks to Anton Veretennikov)
  • Various bug fixes and enhancements

The 1.4.7 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 6:10 AM

Viscosity For Mac: Version 1.4.6 Mavericks Ready!
Tuesday, October 22, 2013

Version 1.4.6 of Viscosity for Mac is now available! This update includes some small final tweaks in preparation for the release of Mac OS 10.9 (Mavericks). It has been extensively tested under Mavericks to ensure the best possible experience for users updating their Mac. While previous releases of Viscosity will still run under Mavericks, we encourage all users to update to this version.

Version 1.4.6 Release Notes:

  • Mac OS 10.9 (Mavericks) support further improved
  • Resolves issue where a static challenge prompt may not occur on a reconnect
  • Resolves issue where high CPU usage could be observed during a DHCP/TAP reconnect
  • Various bug fixes and enhancements

The 1.4.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 10:00 PM

Viscosity for Windows: Version 1.4.6
Tuesday, October 1, 2013

Version 1.4.6 of Viscosity for Windows has just been released! Like the recent Mac update we've greatly improved PKCS#11 support, with it much more straightforward to use for end users. We've also improved two-factor authentication support and made a number of small fixes and enhancements.

Version 1.4.6 Release Notes:

  • Support for static challenge/response added
  • Corrects an issue saving max-routes values
  • Corrects an issue handling incorrect PKCS#11 PINs with saved credentials
  • PKCS#11 certificate names are now presented in a clearer format
  • Localization fixes and improvements
  • Various bug fixes and enhancements

The 1.4.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 5:40 PM

Viscosity for Mac: Version 1.4.5
Friday, September 27, 2013

Version 1.4.5 of Viscosity for Mac is now available! We've greatly improved PKCS#11 support, making it more straightforward to use for end users. We've also vastly improved challenge/response support, making it much easier to implement two-factor authentication in custom OpenVPN environments (check out the forum for some examples).

Version 1.4.5 Release Notes:

  • Optimised memory usage while connected
  • Support for static challenge/response requests
  • PKCS#11 certificate names are now presented in a clearer format
  • Invalid PKCS#11 PINs and locked devices will now be detected
  • Disconnect on idle option will now be correctly saved
  • Spanish localization updates (thanks to Claudio Brandy)
  • Various bug fixes and enhancements

The 1.4.5 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 5:14 PM

Viscosity for Windows: Version 1.4.4
Saturday, April 13, 2013

Version 1.4.4 of Viscosity for Windows is now available. We've focused on increasing the reliability of connections even further, with lots of small improvements and bug fixes. In addition we've added a number of features for enterprise environments, including improved two-factor authentication support and the ability to set machine wide settings and connection permissions.

Version 1.4.4 Release Notes:

  • OpenVPN 2.3 upgraded to version 2.3.1
  • Improved two-factor authentication support
  • Improved DPI Scaling support
  • Creating and editing connections can now be set to require administrator rights
  • Global preferences for all users can now be set
  • Connect on start and after resume improved
  • Reachability checking improved
  • Resolves issue importing a connection with a crl-verify list
  • Resolves issue where certain Advanced commands could be saved incorrectly
  • Resolves potential crash that could occur with non-standard system fonts present
  • French localization updates (thanks to David Caradec)
  • German localization updates (thanks to Dirk Dittert)
  • Several minor bug fixes and improvements

The 1.4.4 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 10:24 AM

Viscosity for Mac: Version 1.4.3
Wednesday, January 23, 2013

Version 1.4.3 of Viscosity for Mac is now available. We've worked hard to resolve all known bugs with this release, improve IPv6 support, upgrade OpenVPN to the latest 2.3 release, and for those Retina MacBook Pro users: menu icons have been upgraded with retina level graphics!

Version 1.4.3 Release Notes:

  • Resolves issue setting/restoring DNS servers when IPv6 is in use
  • OpenVPN 2.3 upgraded to version 2.3.0
  • Retina graphics for menu icon packs
  • Passtos support enabled (for OpenVPN 2.3 only)
  • Improved two-factor authentication support
  • Improved handling when switching network locations
  • Improved handling of No buffer space OpenVPN errors
  • Resolves issue parsing raw IPv6 addresses
  • Resolves issue where iMessage/Push Notifications may not work while connected
  • Keysize support restored for OpenVPN 2.3 (build 1114)
  • Various bug fixes and enhancements

The 1.4.3 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit our support section.

Posted at 11:29 PM

WiTopia's New VPN Client Viscosity Powered!
Thursday, March 1, 2012

We're pleased to announce that WiTopia's new VPN client, available for both Mac and Windows, is powered by Viscosity! Subscribers of WiTopia, a VPN Service Provider, have long received a bundled copy of Viscosity as part of their subscription. However they'll now receive a specially developed client designed for WiTopia's service, with the power and reliability of Viscosity at its core.

We're excited with some of the features we've been able to pack in, such as multi-protocol support, connection auto-updating, smart connecting to the nearest VPN server, and automatic protocol fallback when a particular VPN protocol is being blocked. The client not only supports OpenVPN, but also L2TP, PPTP, and IPSec, meaning users on non-OpenVPN plans will no longer miss out!

We're sure WiTopia subscribers will love the new client (we sure do)! If you are a WiTopia user we encourage you to download and check it out. And if you have any feedback, good or bad, please don't hesitate to send it along to them.

If you're looking for a VPN Service Provider, we encourage you to check out WiTopia and the new client. Or take a look at our VPN Service Providers page for a list of great VPN Service Providers that also bundle and support Viscosity.

Posted at 2:15 PM

Viscosity 1.3.1 For Windows Released
Saturday, July 30, 2011

Version 1.3.1 of Viscosity for Windows is now available!

1.3.1 includes a performance overhaul of Viscosity's background service. We've placed a focus on reducing memory usage by completely rewriting sections that were sluggish or relied on libraries that required large amounts memory. It now has up to 90% less memory and CPU usage, and should resolve any service start up issues.

Version 1.3.1 Release Notes:

  • Performance of the background service vastly improved
  • Memory usage of the background service vastly reduced (by over 90%)
  • Resolved issue where settings may not be correctly processed when bundled into Viscosity
  • Additional bundle options for system administrators
  • Resolves issue where drivers may not be correctly updated
  • Various bug fixes and enhancements

The 1.3.1 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit

Posted at 10:10 AM

Viscosity 1.3 For Mac Released
Friday, May 27, 2011

Version 1.3 of Viscosity is now available for Mac users! It is our biggest update yet, with heaps of new features and performance enhancements!

Version 1.3 Release Notes:

  • Vastly improved network awareness for improved connection stability
  • Vastly improved DNS support
  • Reduced memory usage and performance improvements
  • Ability to automatically reconnect after network dropout
  • Ability to automatically connect when network becomes available
  • Ability to import folders containing multiple connections
  • Improved welcome window design
  • Preferences window can now be resized
  • Viscosity will prompt for elevated rights if necessary to import configs
  • Support for "Before Connect" AppleScripts
  • Support for conditional connecting using Before Connect scripts
  • Support for global Connect/Disconnect AppleScripts
  • Improvements to sleep/wake functionality
  • Improves support for UTF-8 characters
  • Stray/Stuck OpenVPN processes will now be terminated on disconnect
  • Reduced program size
  • OpenVPN updated to version 2.2.0
  • OpenSSL updated to version 1.0.0d
  • OpenVPN 2.0.9 removed
  • Localization system improved
  • Portuguese localization thanks to Denis Volpato Martins
  • Various bug fixes and enhancements

The 1.3 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit

Posted at 8:00 PM

Viscosity for Windows Now Available!
Tuesday, May 24, 2011

We’re very pleased to announce that Viscosity for Windows is now available!

We’ve been working hard over the past 12 months to bring over all the power, ease of use, and design aesthetics of Viscosity for Mac to the Windows platform, and we believe Windows users will be impressed with the results. Windows users now have access to the same powerful and reliable OpenVPN experience that Mac users have come to expect with Viscosity.

Viscosity for Windows isn’t a simple port over to a new platform. It has been designed from the ground up to fit perfectly into the Windows environment. Along with all of the standard features provided by Viscosity, Viscosity for Windows offers many additional Windows-specialized features, including:

  • An attractive Aero optimized interface and connection editor
  • The ability to run under both administrator and standard user accounts
  • Windows style notifications and alerts
  • No UAC prompts or changes needed whenever Viscosity is launched
  • The ability to bundle Viscosity with connections and settings
  • The ability to store username and passwords in the Windows credential system
  • Batch (.bat) & VBS (.vbs) scripting support
  • Much more!

We encourage you to download Viscosity and take advantage of the free 30-day trial period to try out Viscosity for yourself. And like the Mac version, Viscosity is just $9 to buy.

Posted at 5:06 AM

Viscosity and the App Stores
Wednesday, February 9, 2011

Both the iOS and Mac App Stores present a compelling experience to end-users, yet to date Viscosity is unavailable on both of them. Not a day goes by without an email arriving in our inbox asking when we plan on making an iPhone version, and more recently, asking when Viscosity will be available on the Mac App Store. So rather than continue to answer these requests individually, we thought putting up a blog post answering the issue in depth would be a good idea. However just a warning: unfortunately the news isn't good!

Mac App Store

Like other Mac developers we were initially hesitant to submit Viscosity due to some of the App Store policies (no trial period, no discounted upgrade pricing, support, and so forth), but there is no question that the App Store makes installing software much easier for end users. Ultimately we think it will become the main method Mac users will use to find software, so we made the decision to add Viscosity to the Mac App Store if we could. However we can't.

First a bit of background information. When you first run Viscosity is asks for admin rights (or "root" for the *nix folks). This is necessary so Viscosity can create a network interface for your connection/s, setup your DNS servers, and setup the correct routes for your remote network (among other things). Ultimately it doesn't seem like this should prevent an application from appearing on the App Store. After all, the review process should prevent apps that want admin rights for a nefarious purpose, and there are many, many existing Mac applications that require elevated rights so they can integrate with the system. However point 2.27 of the Mac App Store Review Guidelines forbids this:

Apps that request escalation to root privileges or use setuid attributes will be rejected

As you can see, there isn't much in the way of wiggle room there. While we believe we can work around other restrictive points, unfortunately point 2.27 is pretty much a show stopper. We can only hope that Apple change this rule in the future.

iOS App Store

For a long time now we've been getting emails asking us for an iOS version of Viscosity on the App Store. It's something we'd absolutely love to give you guys however unfortunately, like the Mac App Store, there are a few rules preventing such a release.

The two most notable clashes with the App Store rules are that OpenVPN can't run in the background on iOS (without turning to private APIs), and Viscosity needs elevated rights to make the required network changes. While we hoped iOS 4's multitasking implementation would allow us to do the former, it is unfortunately not "true" multitasking. This leaves the conclusion that there is no hope of a Viscosity for iOS release through the App Store unless Apple make some of their private APIs public.

Another interesting point of possible contention has been raised by the recent removal of VLC from the iOS App Store. VLC was removed due to a possible clash between the GPL and the App Store's Digital Rights Management (DRM) scheme. OpenVPN is also licensed under the GPL, so if it was included in a similar fashion to VLC it may also clash. Luckily we don't believe such a clash would exist with Viscosity as the DRM is applied to the Viscosity app itself (not the OpenVPN binary) which is not licensed under the GPL. However the issue still deserves consideration.

While an official iOS App Store release may be out the window, we're still considering a release for jail-broken devices. We cooked up an experimental version some time ago, so we know it's something we can pull off. However at this stage we're focusing on other products (Viscosity for Windows and Viscosity Server). We will no doubt revisit this option at a later date, so if it's something you'd like to see us focus on make sure you let us know via the forums, Twitter or email!


So as discussed above, Viscosity will not be appearing on either App Store due to policies outside our control. We'd love to release Viscosity for both, so we'll be keeping up dialog with Apple in the hope of a policy change that will allow Viscosity to be submitted. We'll continue to support purchasing Viscosity through our website (and you can even try it out for free for 30 days!) and we hope you will continue to enjoy using it (Mac App Store or not)!

Posted at 6:29 PM

End of Year Update
Tuesday, December 21, 2010

With the 2010 almost over we thought we'd take the opportunity to bring everyone up to speed with what we're working on and what we have planned for early 2011 (we're working hard, honest!).

We are very excited to have finally reached the beta phase for the Windows version of Viscosity. If you use Windows (or know someone who does) we'd love for you to download the latest beta and take it for a spin! We need your help spotting bugs and shaping features, so we'd appreciate any comments you can offer. For more information, and for access to the beta, please see this page. Once we're confident all bugs are squashed we will release the full version (we except this to happen very early next year).

Viscosity for Mac hit its two year birthday a couple of months ago, which was a great milestone! We have been working hard on adding features and making general improvements since its release. Looking forward, version 1.3 is in the works, which squashes some bugs, adds improved enterprise and provider support, and greatly eases deployment to end users. We expect version 1.3 to be fully released early next year.

We appreciate all the feedback and interest you've expressed for Viscosity Server. We're very, very keen to have a beta release available as soon as possible, which is likely to be early next year. Our initial plan was to have a beta version available before Viscosity Windows, however based off user feedback we decided to make it our priority to release Viscosity Windows first. We'll be doing everything in our power to bring Viscosity Server to you as soon as possible! We have been promising some sneak peaks, and while we don't think the interface is ready yet, hopefully the following screenshot (of the main status window) will tide you over! Just remember, it's still a work in progress!

We know that many of you are not fans of PayPal (who we use as our primary payment provider). To that end, we have teamed up with RBS Worldpay to allow us to offer a faster and more streamlined store. Over the next few weeks we'll be bringing the new store online, which should hopefully alleviate any issues with PayPal and make purchasing Viscosity much simpler. Paying via PayPal will of course still be an option.

Finally we want to say thank you for your support, great feedback and suggestions, and purchases, all of which allow us to focus on developing great software. Our products wouldn't be the same without you!

Posted at 4:01 AM

Viscosity for Windows Beta Signup
Thursday, December 9, 2010

We're very pleased to announce that Viscosity for Windows has hit beta phase! If you've got a knack for breaking things, able to offer well written bug reports, and willing to offer constructive feedback, we'd love to include you as a beta tester!

Simply click here to visit the beta signup page. You'll get early access to Viscosity for Windows, help shape its features, and a limited number of free licenses will be given away to those who provide the best bug reports and feedback.

Posted at 3:16 PM

Celebrate Viscosity's Birthday!
Thursday, October 28, 2010

Viscosity turns two years old today! To celebrate we're giving away 10% discount codes (for a limited amount of time) to anyone who follows @spark_labs on Twitter!

If you don't already follow our Twitter account, no problem! Simply visit our Twitter page, click the Follow button, wait a few seconds, and then visit the link below.

Click here to visit our promo page and instantly claim your 10% coupon code.

Posted at 10:05 PM

Sneak Peek #1: I wonder what this could mean?
Friday, October 15, 2010

Over the next couple of weeks we’ll be posting up a few sneak peaks of two upcoming Viscosity related products. We’re doing this to give everyone an idea of what we’ve been working on. And possibly as a stalling tactic to allow us to apply the finishing touches before we make beta versions available!

If you’d like to be kept up to date please follow our Twitter feed and/or subscribe to our newsletter.

However for now we present Sneak Peek #1:

Posted at 9:27 PM

Viscosity 1.2 Released
Wednesday, September 15, 2010

Version 1.2 of Viscosity is now available! Version 1.2 is a free update, and includes many new enhancements, such as:

  • Ability to organise connections into folders (submenus)
  • Ability to import directly from a server running OpenVPN-AS
  • OpenVPN upgraded to version 2.1.2
  • Ability to disconnect connections when the computer has been idle
  • Avoids incompatibly problems with the Cisco AnyConnect client
  • Improved performance and memory usage
  • Improved OpenVPN-AS support
  • Changes to IPv6 behaviour
  • Connected/Disconnected scripts are now copied into connection
  • Updated localizations
  • Various bug fixes and enhancements

The 1.2 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit

Posted at 9:03 AM

Viscosity Featured in pfSense Book!
Monday, August 2, 2010

We here at SparkLabs are big fans of pfSense, using it to manage both our work and home networks. We also know a great number of Viscosity users connect to routers running pfSense, so we were very happy to see Viscosity featured in pfSense: The Definitive Guide by Christopher M. Buechler and Jim Pingle.

"If you use OpenVPN frequently, Viscosity is a much nicer client and well worth the cost."

As well as covering a great deal about network setup, the book also contains an in depth section dedicated to setting up pfSense to act as an OpenVPN server. It contains a great deal of information about how to configure and use Viscosity to connect to your pfSense router.

We highly recommend picking up a copy of pfSense: The Definitive Guide if you are interested in setting up your own pfSense OpenVPN server and using Viscosity to connect to it.

Check out the website for more information.

Posted at 4:08 PM

Viscosity 1.1 Released
Thursday, July 22, 2010

Version 1.1 of Viscosity, a free update, is now available! This new version includes many new enhancements, such as:

  • PKCS11 (token/smartcard) support
  • Ability to run AppleScript scripts when a connection connects/disconnects
  • IPv6 Support
  • DNS servers/domains can be edited using the GUI
  • Support for pushed WINS servers
  • Connections can be duplicated
  • Updated TUN/TAP drivers
  • Greater controllability using AppleScript
  • Editing enhancements
  • Various bug fixes and enhancements

The 1.1 update can be automatically installed from inside Viscosity, or downloaded and manually installed.

For support with this version please visit

Posted at 9:56 AM

New Website!
Saturday, July 3, 2010

We've finally put the finishing touches on our new website, so welcome! Feel free to take a look around - hopefully you'll like what you see!

Our new site was a long time coming, however it brings together important information about what we are up to, as well as providing better support for our products. Some of the big improvements include:

  • New Support Page: We've put together a completely new support page with a much larger and more detailed Knowledge Base for all of our products. We'll even be significantly expanding the contents over the coming weeks, so if you run into a problem or have a question you'll have it solved in no time!
  • Faster Downloads and Updates: All software downloads and updates are now distributed via a worldwide Content Delivery Network. Everyone should now see significantly faster downloads and in-app updates, particularly for those users outside the USA. Our web server is certainly sighing in relief!
  • Newsletter & Blog: We encourage you to subscribe to our new newsletter. We'll only be sending it out when we have important information, such as new software, updates, and beta releases, so you won't get spammed to death! In addition, we'll be posting the latest SparkLabs news, thoughts, and answers to common questions on our Blog.
  • Twitter: We've finally joined the Twitter ranks, and hope you'll stop by and say hello, or follow us to keep up to date with software releases and news.

Over the coming weeks we'll be adding more content, and posting up more information and beta signups for upcoming software (such as Viscosity Server). So don't forgot to stop by later on!

For now, we hope you enjoy the changes. Feel free to stop by the forums if you have any feedback or comments about the new site or our software!

Posted at 11:03 PM



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