If you like Florencesoft TextDiff (our Windows software to find the differences between two text files), please feel free to tell your colleagues and write what you think on forums, blogs and Twitter.

TextDiff is a fast way to find the differences between text files. Simply drag-n-drop the files onto its user interface or copy and paste the text into its two text panes. Copy and pasting via the clipboard means that it can compare text regardless of its document type.

One of the most useful features of TextDiff is its ability to leave out unchanged text from its reports, so you can immediately see just the differences. It can also show a variable amount of context on either side of each change.

Its text difference algorithm was written from scratch and distinguishes between text just moved around in a document from additions and deletions. Most other compare utilities, based on the longest common subsequence algorithm, cannot do this in any truly systematic way.

Florencesoft TextDiff can also compare two folders or directories against each other and report the new, deleted and modified files.

Functionality is available to find and remove duplicated items in lists, such as names, countries, ingredients etc.

TextDiff is as equally useful for software developers comparing source code, XML, HTML and scripts as for authors writing reports, essays and articles.

A free 30 day trial of Florencesoft TextDiff for Microsoft Windows can be downloaded from here.

If you do not use Microsoft Windows, you can use our online, web-based text compare tool instead.

There are an almost infinite number of software utilities to find differences in text. Most of them use a variation of an algorithm developed by universities in the 1970s. They all find the longest in-order run of similar text between two documents. Any text outside of this is either marked as a deletion or an addition. This in itself proves to be very useful, although it is far from perfect.

Suppose you make a copy of a document (or software source code file) and then reorder some paragraphs (lines of code). Note you are not making any real changes. Perhaps you are just arranging the methods in a class in alphabetical order. If you compare the modified copy with the original document, you will find most comparison tools will fail. They will mark a reordered paragraph as either a deletion or addition. It is not a deletion or addition, it is just an unaltered line that has moved from the middle of a document to the top.

Could there be a separate step to detect moved text? Well that in itself has many problems. For one, suppose you take a paragraph, change one word in it and then move it from the bottom of the document to the top. How can the software spot that it has been moved, if it has been changed at the same time?

It can get more complicated. Suppose the paragraph isn't changed at all, but just has all its sentences reordered at the same time as being moved around in the document.

Our software product Florencesoft TextDiff for Microsoft Windows addresses the above problems. The color green is used for new text, red for deleted text, blue for text moved up in the document and gray for text moved down. The background color changes from white to alternating use of yellow and light blue to indicate that text has been reordered.

TextDiff is free to use for the first 30 days and can be downloaded from our Downloads page.

Today we added an anagram generator and a Black-Scholes option pricing calculator to the Microsoft Store. We wrote these pieces of software some time ago as a learning exercise, but we think one may be of some amusement and the other of some use.

Our anagram generator has found that one anagram of "Vladimir Putin" is "I, invalid Trump".

The internal web pages for our anagram generator and Black-Scholes option pricing calculator can be found here and here respectively.

Florencesoft TextDiff was written with the original intention of finding the differences between text documents, source code, scripts and XML. However due to its many options, it can also be used to find out how one list differs from another.

Consider the two lists of countries below.

UK	Japan
Malta	Brazil
Spain	Malta
USA	Spain
France	Germany
Malta	UK

We can see that the country Malta has been duplicated in the first list. Duplications interfere with the process of finding out what has been added and deleted. Duplicates can be removed from both lists by using the functionality under the Duplicates menu. Each list has to be processed separately.

UK	Japan
Malta	Brazil
Spain	Malta
USA	Spain
France	Germany
	UK

Now that we have deleted the duplicate, we can find out how the two lists differ. Ensure Whole Paragraph/Line is selected on the Options dialog and that Show deleted and added text in different frames is selected on the main part of the user interface. Ensure Actively look for moved regions is checked. Hit Compare.

UK	Japan
Malta	Brazil
Spain	Malta
USA	Spain
France	Germany
	UK

We can see the results above. The UK is colored gray indicating it is in both lists, but has been moved from the top to the bottom. Malta and Spain are in both lists, were not reordered and so are displayed with black text.

USA	Japan
France	Brazil
	Germany

The previous results were helpful, but there is just one more step. Select Don't show any identical paragraphs. Hit Compare. In the above results, we can see that all the countries in both lists have been omitted. USA and France were deleted from the first list and Japan, Brazil and Germany were added to the second list.