What is an Archive
Archiving is putting stuff in a bag/box, or an envelope.
Software developers tend to work with large numbers of constantly changing files -a typical development project can include thousands of files - source text files, compiled object files, linked executables and their supporting libraries. Each of these files might have as many as 100 or more different versions at progressive stages of development and debugging.
There was a need to group these files together, in part to keep them at the matching level of change, and in part, simply to help organise the files. Picture a marbles collection of ten thousand all of which need to be kept in neat sets. What do you do without bags to put them in?
Developers came up with a tool to do this - simply to take a large set of files and shove them in a box, label it, and put some tape across the top. Then the box could be put up on the shelf, and retrieved at some other time. The tool that does this is called an archiving program. There are two general objectives. The first is to simply group the files together into one file (the box), and give it a name. The second is to take all the air out of the file (white space) so that it takes up less room - this is called compression. There are archives that are not compressed, incidentally, the file format “tar” stands for “tape archive”, and this file is not compressed.
What is Compression
Compression is removing white space from documents, spreadsheets, and binaries (pictures, movies).
There are two general approaches to compression, and most algorithms use both. The first is the simplest. If you type ” ” ( ten blank spaces), you use 10 characters worth of storage. If on the other hand, I replace that with 10!, where “!” means a blank space, then I am using only 3 characters worth of storage. This is not exactly how this is done, but it has that flavour. Files with a large number of empty spaces (particularly word processing documents, spreadsheets, and databases) can be compressed significantly with this technique.
The second approach to compression uses a dictionary tactic. For any given language, there are a set of very common words. In any given piece of text (look at your newspaper) the word money is likely to appear. Suppose I replace “money” which takes 5 characters, with !132, which takes only four characters. I have just reduced the size of the file by one character. Again, this is not the actual technique, but it is analogous.
Some files have a lot of common words, and a lot of white space ( or air), and can be compressed significantly. Others have next to no white space, and few, if any words. Most binary files - pictures, graphics and images, movies, and compiled code files - do not compress very much.
Nevertheless, putting all the files in a single box can be a real advantage for storing, managing and distributing larger collections of files. If the compression rate is decent, then distributing is that much cheaper.
Software for Archiving
There is software that has been available for years to make archives. The best known for the past decade is Winzip, which inherited the crown from the venerable PKzip when Windows became the most widely used operating system. For many years, it has been treated as free, since the software was distributed on the trial basis, and used the honour system to receive a paid license.
Below is a bit of information on three archiving programs. Two are commercial : trial period and buy offerings - Winzip and WinRAR. The third is 7Zip - an Open Source alternative. The two commercial offerings are a bit slicker in look and feel, have somewhat superior web-based support resources, and wizards to assist novices to make their first archives. 7Zip, on the other hand, is free, and once you don’t need the hand-holding of the commercial products, is every bit as competent as the commercial ones.
Here is the link for Wikipedia’s comparison of the archiving packages available, including the three discussed below. You will see that the columns form the product selection criteria discussed under Prices .vs. Costs
Winzip
Winzip was started in 1991 in Connecticut. It is a Windows based utility, that has had over 140 million downloads of its various releases since inception. It started as shareware, with a 21 day trial period after which users were asked to pay for the software. Few did, since the trial period extended forever. It was acquired by Vector Capital (who also own Corel) in 1995, and enforcement by actual trial expiry was introduced.
It developed the “Zip” format, which is still the de-facto standard amongst most users world wide. The Corel group certainly is financially stable, as a publicly traded corporation. Little is known about adherence to quality standards, but as the vendor of the Corel office suite, they have a solid reputation for reliability. Support is typical commercial level support.
Here is their product information page, and there is a link to a short demonstration.
The download requires a valid e-mail address.
Download Time 17 minutes at low speed broadband (DSL)
Trial period is 45 days, and you are asked to purchase the product for $30 U.S. after that, upgrades are $7 US per year, and business support is 18% per year of purchase price
Winrar
The company is RARlab, and its world-wide sales and distribution agent is win.rar GmbH from Germany. The software was developed by Eugene Roshal in Russia in 1993. It developed the proprietary compression structure known as RAR. There are different versions for each major operating system, while WinRAR is for windows. Their financial strength is unknown. There is no information on their quality standards and processes, but the product is mature, and as the developer of a widely used standard format (RAR) they are sufficiently credible, and have won numerous awards by respected review bodies. They have a good reputation for reliability and honesty in their dealings with the install base, and provide solid on-line support.
Here is their product information page.
There is a searchable knowledgebase.
The current version at time of writing is WinRar 3.7.1, and you want to locate the language you prefer, right-click and save-as to a chosen destination on your local hard drive. There are also versions for Linux, Mac, and FreeBSd, amongst others.
Download Time 60 seconds at low speed broadband (DSL)
Trial period is 40 days, and you are asked to purchase the product for $29 U.S. after that, which includes upgrades and support for life.
Open Source 7Zip
Project Time Length & Sponsors
The 7zip project commenced late in 2000, and produced its first offering in 2001. It is headed up by Igor Pavlov as sole developer. As a utility project, it has no formal sponsors.
Quality Standards and Bugs
There have been 783 bugs opened since the project inception. The majority of these have been enhancements to the language translation dictionaries. There have been 97 patches published, and a review of the response times indicates prompt action – often less than a few days, depending on the severity. There are 691 feature requests, indicating strong interest in the future of the product.
There have been 28 “bugs” submitted into tracker in 2007. Of these, 20 have been related to translation changes and upgrades for languages such as Japanese, Turkish, and Belarusian.
The last significant functional bug was this one - in which “ryan_w” found that the product would not do exactly what he needed (archiving a file that a user had open on a remote network), modified the code based on Microsoft’s proposed defect resolution for their operating system, implemented it , tested it, and then reported back to Igor in the project’s tracker. And that is how Open Source works…!
Support Facilities
There have been more than 30,000 messages in the discussion forum for the project, and of these, some 5,000 have sought help – Igor himself provides support here as well as other users. There are video instructions on usage here, and more here.
Open Standards
The product does support open standards, as well as offering their own proprietary standard. They also provide the opportunity to add-on support under license from other vendors for their proprietary compression algorithms.
Development Community says …
The SourceForge Community offers annual awards, and 7zip won for Best Overall Project, and Best Technical Design. There is also a review here.
Users and Implementers
There have been 50,000 or more downloads for the past week, and there have been 33 million downloads since the project started. There have been more than 1,000,000 downloads per month since September of 2006.
The current version at time of writing is 4.57 (released December 6, 2007). Unless you are running Windows x64 (we think you would know), you want the 32 bit version .exe file.
Download time took 35 seconds at low speed broadband (DSL)
Decision Analysis
All three products are leaders in their markets. WinRAR’s financial strength is unclear, but 7Zip is a one-man product. Winzip writes the fewest formats including not writing either 7z or RAR. Nor can Winzip extract ISO or CD image files or 7z archives.
7z is the highest performance file format/compression standard.
Winzip has upgrade costs and support fees for businesses, while WinRAR does not – just the price. 7Zip is, of course, free.
Costs for implementation, conversion and training are equivalent, with a slight nod to WinRAR’s extensive support knowledgebase.
Winzip offers little that the other two do not. 7Zip is the preferred solution on a cost and on a performance basis. This is particularly the case since WinRAR provides an alternative path in case 7Zip’s project lead should retire in the next several years (not that there is any indication that that is likely…).
Decision : 7Zip
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