CoolFormat is a free and open-source source code formatting tool from China. It is universal for many popular programming languages, such as C\C++\C#\CSS\HTML\Java\JavaScript\JSON\Objective-C\PHP\SQL\XML.

MathType is supposed to be the most powerful and professional interactive mathematical formulas editor. It can help users easily insert complex mathematical expressions and symbols into all kinds of documents and apps (such as office documents, web pages, desktop publications, demonstrations, E-learning, Tex, LaTeX, MathML, etc.), and has been widely used in the education, teaching, scientific research institution, engineering, paper writing, typesetting, science test papers editing, and many other fields.

Some PDF files downloaded from the Internet may be protected with password, most of which are "Owner Password Protection" type (used to prevent copying, editing, and printing the PDF file), a few of them will be "User Password Protection" type (also referred to as "Open Password Protection", others can not open it without the correct password). As to the former case, we can use all kind of PDF password removers to remove the passwords directly with ease; but for the latter, the user password is required, or you have to make brute force attacks.

Many external factors can lead to file or data loss (such as: accidentally delete, format some hard disk or partition, virus infection, forcibly remove external storage devices, power failure, system crash, software breakdown...). But their root causes are primarily: MBR (Master Boot Record), BS (Boot Sector), DPT (Disk Partition Table) or MFT (Master File Table) is lost or damaged/corrupted. At this point, the only and ultimate solution that can restore any non-overwritten hard disk data is to use WinHex such kind of hex editor to manually correct them. But that requires you to be proficient in assembly language and the working principle of hard disk. So, what most of us need are some automation tools such like GetDataBack.

BackUp Maker is a very good data, file multi-threading (so it's very fast) backup software from Germany, which is neglected or overlooked but professional and user-friendly. More than anything, it's totally free for both private and educational purposes.