Source Code without Tabs is Superior to Source Code with Tabs

This debate is in regards to computer programming, but anyone is welcomed to accept the challenge. The only caveat is that programmer speak may creep into the debate, though I've made every attempt to avoid undefined geek-speak for the benefit of the readers. Definitions: Source code: The original textual form of a computer program Tab: The digital character representing white space - usually wider than a single character Superior: Having greater value Source Code Readability: The ease to which source code can be comprehended 1. Source code that is more readable is more desirable. Source: http://web.mit.edu... The most expensive phase in any software's lifecycle is the maintenance phase. Furthermore, "The majority of the time and effort expended during maintenance-related activities is code reading." It follows then, that if source code readability can be improved, corporations reduce costs and programmers save time. Saving time or money is generally more desirable than losing time or money. Therefore, source code that is more readable is more desirable. 2. Formatting plays a significant role in readability. Several factors contribute to readability, such as useful comments, well named variables, and indentation of code blocks. Formatting, the use of white space to position source code text in a meaningful way, is of great importance in readability. Indenting blocks of code, formatting comment blocks, and right aligning variable initializations or post-statement comments, all serve as landmarks to the reader, directing attention to where it's needed to assist in reader comprehension. Similar techniques are used in magazine articles, websites (including this one), books, etc. Thoughtfully formatted code increases the ease to which source code can be comprehended. Therefore, source code with superior formatting will also have superior readability. 3. Tabs cannot guarantee original formatting. Tabs are not directly portable. That is to say, tabs are not guaranteed to appear the same from one system to the next or from one user to the next. The original source code author might operate within an environment that treats tabs as whitespace equivalent to the width of 4 spaces whereas another programmer might use 2-space tabs. Worse yet, a manager might open the source code in Microsoft Word, in which case, the tabs are based on inches instead of characters. While such differences may not hinder leading indents, right aligned blocks of code such as post-statement comments might lose their alignments. Since tabs are system and user independent, they cannot be a guaranteed method for preserving original formatting. 4. Guaranteed original formatting improves readability When using tabs, a source code document has a potential readability. If the document is read by the same user or another user with the same settings, then the document's actual readability is equal to its maximum potential readability. If, however, it is read by a user with different settings, the document's actual readability is less than its maximum potential readability. When using only spaces, there is no potential readability, only actual readability. Or said another way, the document's actual readability is always equal to its maximum potential readability. Therefore, guaranteed original formatting improves readability by ensuring that no readability can ever be lost. I have shown that using tabs creates a potential for decreased readability. Given that readability accounts for a significant part of software maintenance, the more readable the source code, the more desirable and valuable it becomes. Hence, source code without tabs is superior to source code with tabs.