Biggest Twitter IPO Non-Winners Helped Invent Key Features Today some of the inventors and founders of Twitter stand to make millions of dollars as the social network goes public on the NYSE as TWTR. However, the inventors of some of the core features of the service, including the famous hashtag, the @ reply and the retweet won't make a penny today, at least not off Twitter. And that's not because of corporate greed or unlucky circumstances, it just turns out that some of the main features of the newly public service that lets you share 140-character messages were all invented or thought up by average users with no stake in the company. They were just regular users of a small social network that now is valued at $18 billion and has 230 million active users. The Father of the Hashtag That was the first tweet that proposed the idea of using the pound symbol to group tweets on a specific topic and it was fired off by Chris Messina, who was working for his own consulting agency at the time. Messina decided to start adding hashtags to his own tweets gradually and he then wrote up a proposal for the idea. But it wasn't until the San Diego forest fires in 2007 that they started catching on, he told ABC News. "It wasn't until the fires in San Diego where I was able to convince my friend Nate Ritter to start using them for the purpose of citizen journalism that they actually really found a general purpose," he said. After that, they continued to be adopted far and wide, until brands started to use them in completely unexpected and public ways. Today Messina, 32, is the Head of Community & Growth at NeonMob. He has never been an employee of Twitter nor has he invested in it. He won't make any money off the IPO today but does plan to buy stock in the company. "I'm investing in the future of social technology and the continued digital innovation that companies like Twitter represent," he says. The Father of the @ Reply On Twitter the way you recognize others or can tweet to them is by including the @ symbol and then the handle of that person. But it wasn't always like that. Robert Shane Anderson is widely credited as being the first person to insert the @ symbol before a username on Twitter. When my brother Buzz wrote a tweet about breaking his thumb, I wanted to reply where I saw the message. The @ symbol as a targeted-reply was a convention that I had seen people using on the Internet at various points in time, so I guess it was just a stream of consciousness that led me to doing it," Anderson told ABC News. I didn't even know I was making history, and I think to a large extent the convention would have been adopted regardless. At the time Anderson or @rsa on Twitter was 18 and was working as a self-employed interface designer. He has never worked at Twitter though now is the Creative Director at Square, a mobile payments company started by Twitter co-founder Jack Dorsey. He doesn't own any stock in Twitter and says he isn't sure he'll buy. He is sure that Twitter has a bright future, however. The Father of the Retweet Like the @ Reply and the hashtag the Retweet started with a user named Eric Rice throwing the word "Retweet" in front of a friend's message. "I honestly don't remember if I had seen it before or how I came to use it," Eric Rice, 41, told ABC News. The retweet itself was just an off-handed share of a late friend's comment on the state of social media at the time (and was one of the last tweets of his life). At the time Rice was working at podcasting company. He has never worked at Twitter and doesn't have plans to buy Twitter stock. Rice kept using "retweet" in tweets, but according to this post from Mediabistro, the first tweet to use the more popular RT method came from @TDavid on January 25, 2008. In November 2009, Twitter incorporated a retweet feature.