This highly visual and responsive VB6 application is an implementation of the global sequence alignment algorithm. It allows the modification of the alignment parameters (match, mismatch, gap), and it shows the pairwise alignment as well as the score matrix in real time. Moreover, it shows the score matrix values as a heatmap and the traceback path of the current alignment. Many predefined experiments are available to the user for certain observations related to the global sequence alignment algorithm. Also, changes to either of the two sequences lead to a real-time pairwise alignment. The purpose of the algorithm is to seeks the optimal alignment between two text sequences. Why is this optimal alignment so important? To find similarities between two words, a manual comparison is required. For words between 4 and 8 letters, such a task can be performed by any of us without the use of a computer. However, what if the objects of comparison are entire phrases/sequences/files? Then the number of possibilities for different matches increases exponentially and nobody can do it by paper computing (to my knowledge). Computational solutions for these problems exist, such as different implementations of sequence alignment algorithms. Here, the implementation of global sequence alignment is shown in detail. Note that the implementation si designed in Visual Basic 6.0. Note: This VB6 application has a child in javascript that can be opened directly in the browser here.

• Paul A. Gagniuc. Algorithms in Bioinformatics: Theory and Implementation. John Wiley & Sons, Hoboken, NJ, USA, 2021, ISBN: 9781119697961.