David R. Heffelfinger

After I implemented and deployed the PDF Unlocking Tool, I was fortunate to find out it became very popular. Apparently I had written and deployed a useful tool.

It's popularity got me thinking, what else I could write that would be helpful to others? Then it hit me, just like PDF files are sometimes restricted, preventing users from copying and pasting their content, sometimes Excel spreadsheets contain locked, uneditable cells.

I started looking around for Java libraries to manipulate Excel spreadsheets, and found JExcelAPI. I started researching this library and sure enough, I found a way to unlock cells in an Excel spreadsheet.

Using this API, I developed an online utility to unlock cells in a spreadsheet, which can be found at http://ensode.net/xls-crack.jsf. It soon became a very popular destination on my site.

Ubuntu Hardy Heron is my primary operating system. Although in general I think it is a great operating system, there was one little annoyance that was bothering me. Firefox 3 always started in offline mode.

Every time I opened Firefox I had to go to the File menu, and uncheck the "Work Offline" checkbox, very annoying.

Well fortunately I found a solution. In order to avoid this from happening, we need to type "about:config", then set the toolkit.networkmanager.disable preference to true. Problem solved.

A while back I purchased an ebook in PDF format. When I tried to open it under my Linux laptop I got an unpleasant surprise, the ebook's author had used a font that wasn't available on my Linux box, therefore the ebook was unreadable.

I figured I can simply copy the text and paste it into a text editor or word processor, but to my dismay I found out it wasn't possible to copy text from the PDF.

I had heard about iText, a Java library used to create and manipulate PDF's. I studied the iText API and found out how to make a copy of the PDF with the copy/paste restrictions removed. I wrote some code to try it out, and lo and behold, I was able to copy and paste from my custom copy of the ebook.

I figured that just like I needed to remove those restrictions, many others out there probably had the same problem. I turned my home grown utility into a web application and posted it on my site: http://www.ensode.net/pdf-crack.jsf. It has been helping people remove those annoying restrictions for a while now.,