In Windows zooming is done by holding th Ctrl-key down and use the mouse wheel to zoom in or out. On a trackpad you have to look in your documentation. Every trackpad supplier has his own way to make the mouse wheel function working. For Apple you can look here http://alvinalexander.com/blog/post/mac-os-x/how-zoom-in-zoom-out-mac-osx-screen or here http://www.wikihow.com/Zoom-out-on-a-Mac.
The latest versions of the most known browsers should support the content of this site. The only browser that gives problems and unpredictable results is Microsoft Internet Explorer (IE). The lower versions (lower then version 9) don't handle HTML5 at all in a correct way. The versions IE 10 and lower are not any longer supported by Microsoft. If you want to use IE, version 11 is the only one. With Windows 8 Microsoft introduced a new browser: Edge. Their own advice is to use Edge instead of IE, which will also be discontinued in the near future. As the market share of Microsoft browsers (IE and Edge together is about 10%) we will only pay attention to Edge and leave out IE.
We have tested the following browsers:
They all behaved more or less as expected. The differences between them are mostly optical (the PDF viewers and the audio/video players). We already noticed that Firefox has some trouble with the video files. Sometimes it takes quite long before they are loaded. When scrolling through the Albanian file it takes a long time before it continues at the new position. Sometimes after scrolling the sound is very distorted. Edge and Chrome handle video just fine. Safari we will test later.
Microsoft Edge is a relative new browser, introduced with the launch of Windows 8. On the Internet you can find a lot of items about problems with video and audio in Edge. In some cases Edge stops playing video or audio. A possible solution can be to empty the cache, cookies and browser history. To do so, click on the three dots (...) in the right top corner of the browser window. The "Settings" menu will drop down. Click the "Clear Browsing Data". Here you can empty the cache, delete cookies and the browser history. It worked on our PC's but not on a tablet. Probably due to insufficient memory (2 GB).
If you select a PDF in "Collection" in Firefox and it will start download that PDF instead of showing the content directly, you can do the following to change this (according to information of Mozilla, the developer of Firefox):
In our situation this did not work. We made a test to choose the Bulgaria PDF in "Collection". This is the biggest PDF in "Collection": 47 megabyte, 88 pages in A4 format. We tried three most used browsers and emptied the cache first. The following number of seconds were found before the first page was shown: Edge 22, Google 15 and Firefox 150.
There is a better solution for Firefox. If you have a PDF reader installed on your system (e.g. Acrobat Reader) the best option is to choose that reader in step 3. If a PDF reader is installed you see it as an option where you choose "Preview in Firefox".
Since the introduction of HTML5, there has been created a mechanism to cache each page you asked from the server. This has been done to make off line working possible and to reduce traffic with the server. The browser looks in the cache if a requested page is already there. If not, the request is redirected to the server. If there is a new page on the server and an old one in the cache, you will see the old one and you will get unpredictable results.
There is a lot of discussion about this topic on the Internet and solutions or work arounds. We have to look what is the best solution for our site. We are working on it!