Collapsing single newlines is a love-it-or-hate-it feature. Personally I like it because it allows me to place one sentence (or clause) per line, which makes ve

Collapsing single newlines is a love-it-or-hate-it feature. Personally I like it because it allows me to place one sentence (or clause) per line, which makes version control much easier. But a lot of people seem to hate it with a passion, and I can also understand their frustration because it just isn't intuitive to anyone who doesn't already know how HTML treats whitespace. Things that actually do annoy me from time to time: - In the default implementation, an underscore in the middle of a word causes the rest of the word, and everything until the next underscore, to be italic. Fortunately, most of the actual implementations have fixed this, but that ain't standard. I also don't think Reddit has fixed it yet. - Using one asterisk OR one underscore for <em> and two asterisks OR two underscores for <strong> feels redundant. There is no need for two different syntaxes to achieve the same effect. I would prefer one underscore for <em> and one asterisk for <strong> (email clients have been doing this for plain-text emails for a long time), but maybe that's just me. - AFAIK there is no built-in syntax for underline, strikethrough, superscript, and subscript. Maybe we should repurpose some symbols to handle such cases. On the other hand, there are things the article complains about that I absolutely don't think need to be "fixed": - HTML filtering/escaping. Seriously? There are plenty of excellent HTML filters in every language. No need to reinvent the wheel. Just pipe the stdout of your Markdown parser to the stdin of your HTML filtering library. In addition, some of us use Markdown to write our own blogs, where we have every right to insert an occasional <script> or <iframe>. You know, like embedding a YouTube video. Different people should have different rights to use one or another HTML feature, and managing such rights should be the job of your app, not your Markdown parser. - Any sort of Wiki markup, like Creole. The distinguishing feature of a Wiki markup is that it makes it easy for users to cross-reference documents. But in order to cross-reference documents, we need to agree upon some sort of document organization system. But given the very diverse situations in which Markdown is used, is it even feasible to agree upon a single such system? It would seem that the only cross-reference mechanism that is compatible with all the things we use Markdown for is the good old URL, and Markdown can already handle URLs pretty well. Converting URLs to something that references another place within your app should be the job of a pre-processor/post-processor. Don't be afraid to write one.