To assess the damage that CSS vendor prefixes could do to the Opera Browser, we have created a script that looks at the type of CSS used for certain properties. This survey has been run by Karl Dubost (twitter: @karlpro) for Opera Developer Relations in August 2012.
This survey (and associated scripts) is meant to give an idea of what is done on the web with regards to using prefixed properties. Statistics "lie". That's their goal.  On the other hand, users browsing the web are all about individual cases. A specific site will break for a specific user of a specific browser. The fact it is breaking for a small market share, for a single country, etc., doesn't remove the fact that it is breaking. In the results below, you will notice we didn't give any percentages. A finer grained analysis with a manual checking is necessary to give relevant percentages and associated error margins. The numbers are here to show a trend and difficulties that might result from it.
Before going into the results, we will provide information on the data set, what we tested and the many caveats of this survey.
Everything about this survey is open source, released under an MIT License — you are welcome to take the source code and run your own modified version. It would be appreciated though if you could submit patches, suggest features, etc. This is a first draft or alpha if you prefer. A lot of things can be done to improve and make it more useful for all of us.
We used Alexa's top 1000 sites list (2012-07-30), extracted from the top 1 million sites. Alexa provides a list of domain names only, in the following format:
970,opera.com
We applied a transformation, so we could get a URI to process:
http://opera.com/
Obviously the main web site address will sometimes be different. See the section on caveats
We used two user agent strings (one for mobile and one for desktop) and ran the survey twice to assess if the results are different.
For Opera desktop:
Opera/9.80 (Macintosh; Intel Mac OS X 10.8.0) Presto/2.12.363 Version/12.50
For Opera Mobile:
Opera/9.80 (Android 2.3.5; Linux; Opera Mobi/ADR-1202082305; U; en) Presto/2.10.254 Version/12.00
We logged a few things in the log file. The main data about vendor prefixes is expressed with lines such as:
2012-08-14 11:31:50,127 - INFO - SURVEY: http://www.opera.com/ ['transition', 'moz', 'o', 'webkit', 'prefixless']
The data items — from left to right — are:
prefixless
means that the property is present without prefixes .There are other things logged into these files — we'll let you explore them for now, although it might be necessary to document them later on. The script is raw on the edge and the logs are too. Any proposal for improving the log and the storage of results to make it more usable are welcome. We compiled the results using a combination of sed, grep, uniq, sort and awk — they are fast, flexible and do the job. But we are open to better ways of doing it.
To extract all the lines related to the survey. sort
is used to put similar lines in order . uniq -c
will compile and count the same lines:
grep "SURVEY" log-2012-08-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c
We can then extract related items, for example transition
:
grep "SURVEY" log-2012-08-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transition'
or items related to a specific web site such as youtube:
grep "SURVEY" log-2012-08-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'youtube'
This will give us all sites which are not adding -o-
in their rules:
grep "SURVEY" log-2012-08-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep -v "'o'"
And the sites without -o-
AND without the prefixless property:
grep "SURVEY" log-2012-08-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep -v "'o'" | grep -v "'prefixless'"
The script has many flaws. First, it has been written by me (Karl Dubost). It uses three external libraries — Requests, lxml, cssutils — and the script might be dependent on the bugs of these libraries, in addition to its own bugs. Some of its caveats are described in the following sections.
The script is not really very fast, so there are certainly issues to address if we wanted to process a larger volume of data. The sample of 1000 sites took around 7 hours and 22 minutes (442 minutes) to process; 1 site every 26.52s (as a mean). Some sites takes longer than others. The process order is as follows:
We could probably improve the performance of the script by first downloading all the resources and analyzing them locally. It's a path to explore for future versions. That would greatly help for running stats on the same sample of data.
Alexa has domains from different countries, but it is not necessarily representative of the local sites used for each country. This is important when addressing specific local market shares. It is usually hard to have a good overview for each country, so in this report, we are not trying to address this aspect of the data. It would be an interesting additional study to do for this survey and explore the differences between the markets.
Because we are starting with a URL, which is based on a domain name, some sites will redirect the HTTP requests according to the user agent. For example, for the Opera domain we first access http://opera.com/
then http://www.opera.com/
. When accessing with the mobile user agent, we get additional redirections for certain sites such as sfgate:
Starting new HTTP connection (1): sfgate.com "GET / HTTP/1.1" 302 235 Starting new HTTP connection (1): www.sfgate.com "GET / HTTP/1.1" 302 39 Starting new HTTP connection (1): m.sfgate.com "GET / HTTP/1.1" 302 0 "GET /sfchron/index.htm HTTP/1.1" 200 None
The script is interacting at the HTTP layer and doesn't have a JavaScript interpreter. So all sites dependent on JavaScript for redirecting the browser have not been working accordingly to the intent of the owner. It can be difficult to assess the exact mobile version:
On the Mobile survey, the results then are a mix of mobile (the redirection happened) and desktop Web sites (there was no redirection for one the previous reasons). We tried to figure out roughly the number of redirections. There are some patterns with domain names:
grep "Starting new HTTP connection" log-2012-08-opera-mob.txt | sed "s/.*connection (1): //" | uniq | grep "^m\." | wc -l
152 domains starting with m.
:
grep "Starting new HTTP connection" log-2012-08-opera-mob.txt | sed "s/.*connection (1): //" | uniq | grep "^mobile" | wc -l
24 domains starting with mobile
(a handful had a completely different domain name):
It is another issue to solve and re-run the survey for only mobile Web sites.
We parsed only CSS set through a style
element or a link rel
element. We did not take into consideration styles set through the style
attribute, @import
s or through JavaScript. Some sites modify their CSS depending on the user agent and a few other rules.
In this first run, we tested only shorthand properties, so individual property rules (either hardcoded or created by CSS generators) are not counted in this current survey. The main code has to be modified to take into account these cases. We opened issue 13 to account for this.
It would also be interesting to assess what the ratio of sites using the shorthand properties compared to the full individual rules is.
The results given in this report do not equate to the featured web sites being completely broken for their users. It would require a lot of work by a big group of volunteers for testing each individual site on the list to assess site compatibility for each browser.
The data for the survey is available on github. Feel free to reuse them and point out mistakes. As we said before this is much a work in progress and we have certainly made mistakes. Read the introduction again … it is imperfect.
Usually high traffic Web sites try to keep the number of HTTP requests to a minimum, because the time an HTTP request takes to be completed is significant to the overall performance of the Web site. Because we were requesting the Web sites' CSS URLs, we took the opportunity to count them.
| link rel | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 to 22 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Desktop | 187 | 266 | 202 | 114 | 69 | 40 | 26 | 14 | 14 | 13 | 4 | 8 | 0 to 2 |
| Mobile | 262 | 295 | 188 | 85 | 53 | 27 | 14 | 13 | 6 | 8 | 3 | 4 | 0 to 2 |
link rel
elements.link rel
elements.link rel
elements.On the Desktop survey, 492 of the 1000 Web sites were using one or more style
elements. On Mobile, this number was 455 Web sites.
There are certainly a few graphs needed to make this easier to understand. Be my guest.
transition
propertyLet's take a look at transitions, and how many of the 1000 sites used them at least once. In each case we are looking for something along these lines:
.foo { -webkit-transition: background-color linear 1s; -moz-transition: background-color linear 1s; -ms-transition: background-color linear 1s; -o-transition: background-color linear 1s; transition: background-color linear 1s; }
Let's grep:
grep "SURVEY" log-2012-08-opera-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transition' | awk '{print $2}' | sort | uniq | wc -l
Below you can see the numbers of sites found that use this property, with the number of sites which have all vendor prefixed versions of this property in at least one CSS rule on the site (['transition', 'moz', 'ms', 'o', 'webkit', 'prefixless']
)
What about the frequency for each vendor prefix?
grep "SURVEY" log-2012-08-opera-mob.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transition'| grep "'o'" | awk '{print $2}' | sort | uniq -c |wc -l
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 187 | 175 | 78 | 140 |
| Mobile | 169 | 143 | 53 | 117 |
We can see that web developers are most commonly using -webkit-
, then -moz-
, then -o-
, then -ms-
, meaning IE will have the hardest time of all of the browsers.
How many of thee sites used transition
without the prefixless property? This is important, because these are Web sites which are likely to break once browsers stop using the prefixed versions. It shows also how much a browser vendor might be encouraged to drop their prefixed properties, or not. Remember when a site is breaking, it is breaking for individual people. Below you can see how many of those sites didn't used the unprefixed fallback for trandition
.
.foo { -webkit-transition: background-color linear 1s; -moz-transition: background-color linear 1s; -ms-transition: background-color linear 1s; -o-transition: background-color linear 1s; }
Let's look again at the frequency for each vendor prefix, but this time without the prefixless version alongside it.
Why this is interesting? Because it shows the ability for a browser vendor to drop the prefixed version from its implementation. If the prefixed version is dropped and there is no prefixless version, the site will break for this specific browser. And the irony of this situation is that it is indeed a lot harder for webkit to drop prefixes than other browsers because a lot more sites will break. Basically, web developers used only -webkit-
prefixes in many CSS rules without the prefixless fallback, creating issues for other browsers now and creating issues for webkit in the future.
grep "SURVEY" log-2012-08-opera-mob.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transition'| grep "'o'" | grep -v "'prefixless'" | awk '{print $2}' | sort | uniq -c |wc -l
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 72 | 42 | 10 | 27 |
| Mobile | 80 | 33 | 7 | 14 |
How many of these sites without the prefixless version use only one vendor prefix, such as
.foo {-webkit-transition: background-color linear 1s;}
For example to extract web sites using only -webkit-
, we could use this:
grep "SURVEY" log-2012-08-opera-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transition'| grep -v "prefixless" | grep -v "'o'" | grep -v "'ms'" | grep -v "'moz'"
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 39 | 0 | 0 | 1 |
| Mobile | 51 | 0 | 0 | 0 |
We can start to feel the disturbance in the force. Basically some sites have CSS rules targeting only WebKit. If you are wondering about the 1 site in Desktop that only targets Opera, it is Facebook — which has 10 CSS rules with an -o-transition
only. Remember the survey has been run with an Opera user agent; I suspect Facebook sends different stylesheets to different user agents. To verify:
10 http://www.facebook.com/ ['transition', 'o']
Often the sites use a -webkit-
prefix only for one or two CSS rules, but then use other vendor prefixes elsewhere in the code. This could be the result of more than one person working on the CSS with different coding styles, or it might be just negligence.
What is a lot more disturbing is the following list of mobile web sites, which (if we have not made a mistake) only have -webkit-transition
, with no rules at all for other vendors. Why is it disturbing? Because these sites have taken care of identifying the Opera Mobile user agent, redirected in most cases to the mobile site, but still served CSS that will create difficulties or incomplete user experiences for this specific user agent.
# mobile sites list http://3g.kaixin001.com/ http://java.com/en/ http://m.avito.ru/ http://m.bing.com/?mid=10006 http://m.livejasmin.com/en/home http://m.myspace.com/home.wap?bfd=webnext http://m.nordstrom.com/ http://m.photobucket.com/?src=www http://m.retailmenot.com/ http://m.sears.com/ http://m.subito.it/ http://m.taobao.com/?sprefer=sypc00 http://m.tmall.com/?sprefer=sypc01 http://mi.nba.com/_touch/ http://mobile.news.com.au/ http://mobile.wetter.com/ http://tw.m.wretch.yahoo.com/ http://wap.sogou.com/?fr=s-sogou&clk=s-sogou http://www.buzzfeed.com/?s=mobile http://www.etsy.com/ http://www.tripadvisor.com/ http://www.verizonwireless.com/b2c/index.html http://www.wikia.com/Wikia https://online.citibank.com/US/Welcome.c https://www.outbrain.com/
There are only 5 domains using transition
without any prefixes.
transform
propertyWe have applied the same type of queries that we used for transition
to the transform
property as well. To find any combination of prefixes, we can use this:
grep "SURVEY" log-2012-08-opera-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transform' | awk '{print $2}' | sort | wc -l
Below you can see the number of sites that use at least one transform
, with the number of sites that have all vendor prefixes (['transform', 'moz', 'ms', 'o', 'webkit', 'prefixless']
) in at least one CSS rule in parentheses:
What is the frequency for each vendor prefix?
For Opera, for example:
grep "SURVEY" log-2012-08-opera-mob.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'transform'| grep "'o'" | awk '{print $2}' | sort | uniq -c |wc -l
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 96 | 88 | 40 | 64 |
| Mobile | 110 | 75 | 28 | 50 |
How many of these sites without the prefixless version use only one vendor prefix?
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 18 | 0 | 0 | 1 |
| Mobile | 48 | 0 | 0 | 0 |
animation
propertyWe are applying the same type of queries again, to the animation
shorthand property. To find any combination of prefixes, we can use this:
grep "SURVEY" log-2012-08-opera-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'animation' | awk '{print $2}' | sort | uniq | wc -l
Below you can see the number of sites that use the animation
shorthand property at least once, with the number of sites that have all vendor prefixes (['animation', 'moz', 'ms', 'o', 'webkit', 'prefixless']
) for at least one CSS rule on the site in parenthesis:
What is the frequency of each vendor prefixes?
For Opera for example, we can use this:
grep "SURVEY" log-2012-08-opera-mob.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'animation'| grep "'o'" | awk '{print $2}' | sort | uniq -c |wc -l
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 24 | 21 | 11 | 10 |
| Mobile | 22 | 10 | 4 | 3 |
How many of these sites without the prefixless version are using only one vendor prefix?
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 2 | 0 | 0 | 1 |
| Mobile | 11 | 0 | 0 | 0 |
Notice that the situation for the shorthand animation seems less problematic. As mentioned in the caveats we would have to double check for the individual properties. Still we can take this as a good sign.
background-size
propertyWe are applying the same type of queries again for the background-size
property. To search for any combination of prefixes on this property, we can use this:
grep "SURVEY" log-2012-08-opera-dsk.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'background-size' | awk '{print $2}' | sort | uniq | wc -l
Below you can see the number of sites found that have at least one instance of the background-size
property present, with the number of sites that have all vendor prefixed versions (['background-size', 'moz', 'ms', 'o', 'webkit', 'prefixless']
) present in parentheses:
What is the frequency for each vendor prefix?
For Opera for example, we can find out like this:
grep "SURVEY" log-2012-08-opera-mob.txt | sed 's/^.*SURVEY: //' | sort | uniq -c | grep 'background-size'| grep "'o'" | awk '{print $2}' | sort | uniq -c |wc -l
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 23 | 23 | 5 | 16 |
| Mobile | 59 | 34 | 5 | 20 |
How many of these sites without the prefixless version use only one vendor prefix?
| vendor prefix | -webkit- |
-moz- |
-ms- |
-o- |
|---|---|---|---|---|
| Desktop | 2 | 0 | 0 | 1 |
| Mobile | 16 | 0 | 0 | 0 |


Google Fonts Clone
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Bonnie E. John, David E. Kieras
"this article focuses on that subset of GOMS research that has reached sufficient maturity to be tools in the engineer’s toolbox of design"
"The overall motivation for GOMS and other HCI cognitive modeling efforts is to provide engineering models of human performance. In the ideal, such models produce a priori quantitative predictions of performance at an earlier stage in the development process than prototyping and user testing...That is, they predict execution time, learning time, errors, and they identify those parts of an interface that lead to these predictions, thereby providing a focus for redesign effort."
"rather than replacing user testing, the current engineering models are best viewed as reducing the amount of user testing required to develop a highly usable system"
[ my italics ]
" goals are simply the user’s goals, as defined in layman’s language"
" Operators are the actions that the software allows the user to take"
" Methods are well-learned sequences of subgoals and operators that can accomplish a goal"
" Selection rules are the personal rules that users follow in deciding what method to use in a particular circumstance"


{first name} {last name}
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Address:
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Gospel Singer Wahu Kagwi Arrested, Arraigned For Dangerous Driving
by Eva NyamburaGospel musician Wahu Kagwi was on Thursday arrested and charged for causing obstruction, driving without a valid driving license and dangerous overtaking.
The businesswoman was apparently driving a Mercedes Benz 440L when the incident occurred. It was around 10.10 am along Ring Road, Kileleshwa.
Wahu was arraigned at Milimani Law Courts before magistrate Elector Riani where she denied the charges.
Read: Policeman Tests Positive For Drunkenness On Alcoblow After Eating Buns -Video
She was also charged with dangerously overtaking several vehicles and obstructed other road users by parking her car on the pathway.
She has since been released on a Sh15,000 cash bail.
The case will be heard later on in the day.
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A Silver Ranger is the highest form of Elven archer. A worthy opponent for Human Hawkeyes.
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This is the OSGi powered enterprise Axis2 platform brought to you by WSO2 Inc. Please use the left hand menues to make use of the components available.


{% comment %}
This sets up a basic input field to use bootstrap's form controls
Variables you need to set in order to use this:
"field" should be the field from the form, e.g. field=form.my_field
Optional vars:
"multiple" boolean indicating if this is a multiple select field or not.
"label_classes" class(es) for label. Used in combination with select_classes, this would allow you to do inline
forms
"select_classes" class(es) for the select input
{% endcomment %}
{% include 'common/forms/field_errors.html' %}
{% include 'common/forms/field_help_text.html' %}


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This example demonstrates how to create a DICOM Segmentation object.
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Drag and drop DICOM files here...
Segmentation header:


Bodyguard Jax:
Royal Guards of the Lord? Gold of Prince Ashiton? What are you talking about? Are you drunk?
Show him the Map of Rambert