One of the reasons why software becomes bloated is because the developer wants to gain new users with clever new features, and it wants existing users to upgrade by offering more features than they currently have.
Software becomes bloated with features and this increases the space required on the disk and the speed at which it runs. This is most noticeable on a laptop that uses a traditional mechanical disk drive because these contain the slowest form of long term storage. Desktop PCs have faster disk drives and SSDs (solid state disks), really fly of course. Software bloat is less of a problem with a super fast SSD in your desktop or laptop PC.
Not only may bloated software run more slowly, it may contain tens or even hundreds of features that you never use. PDF tools are a case in point and all I require from a PDF viewer is to be able to read a PDF document on the screen - eBooks, manuals, invoices, purchase orders and so on. My requirements are very simple and only once in a blue moon might I print out a PDF, but mainly I just want to display them on the screen so that I can read them.
Windows 7 does not have a PDF viewer.
Windows 8 has a built in Reader app that can display PDFs, but an irritating problem with it is that it is a modern Start screen app that runs full screen. This makes it very awkward to use when I need to refer to the contents of a PDF document while using another app, like a spreadsheet or word processor. I cannot have the PDF and word processor documents open side by side and must switch between full screen the Reader app and a desktop window.
Windows 10 is slightly better and by default, PDF files open in Edge, Microsoft's web browser. It is OK and at least it isn't a full screen app. However, it isn't the best PDF reader around.
This means that a separate PDF viewer can be beneficial and the obvious choice is Adobe Reader. However, this has an installed size of 161 MB and it is a large program with a comprehensive and wide ranging feature list, nearly all of which I would never use.
The small, lightweight alternative that I used to use was Foxit Reader and it was excellent. It didn’t have as many features, but it did everything I wanted. I regularly receive emails announcing that the latest update has this or that new feature and the software has grown and become almost as big and bloated as Adobe's tool, taking up over 100 MB of disk space. Foxit Reader is fine if you want a feature-packed alternative to Adobe Reader, but I just want to view PDFs.
I currently use Sumatra PDF, which is a tiny program that is a 3 MB download and is just 6 MB when installed. Adobe Reader is 161 MB remember, and Foxit Reader isn't much less, so this is a huge saving. It’s not that I need to save disk space and with mechanical disk drives offering capacities measured in terabytes, I have hundreds of gigabytes free. The speed at which it Sumatra PDF loads is more useful, and not being packed with features makes it quicker to use too.
Foxit Reader’s extra large Office-like ribbon just gets in the way, whereas Sumatra PDF has just a tab and a slim toolbar. There is a button in the top left corner that provides access to the usual application menus. It is clean, simple, and just what I need.
Not everyone will like Sumatra PDF because it does lack many advanced features of Foxit and Adobe's software, but unless you are a PDF power user, it will be sufficient for your needs. It certainly suites me. Another plus is that it can be downloaded as a portable app that does not need installing. This enables you to keep it anywhere on your disk drive or carry it on a USB flash drive.
It is not completely devoid of features and the home screen shows thumbnails of recently accessed PDF documents, you can view single or facing pages, book view or continuous view, zoom in and out, add pages to favourites, search, print and so on. These are all features I regularly use.
If you would like a PDF viewer that is more powerful than Sumatra, but don’t want the size and complexity of Adobe Reader or Foxit Reader, try PDF-Xchange (ignore the request for the Pro serial number to use it for free). This is a 40 MB app, so it is more powerful than Sumatra, but less powerful than Adobe and Foxit. A happy medium, for the moment anyway. Let’s hope it doesn’t become too bloated.