Fortune Article

Twitter

Twitter inevitably comes up in every IPO discussion, but it's still unclear whether it will file to go public in 2013. Twitter's top management has consistently put off the idea that an IPO is looming, most recently in a CNBC interview with CEO Dick Costolo in September. The company has its pre-IPO ducks in a row, including strong management and tremendous growth potential. eMarketer predicted Twitter's 2013 revenue at $545.2 million in October, that's an estimated growth of nearly 88%. If the social media site can meet these lofty revenue targets, an IPO decision might be an easy one to make.

Violin Memory

Violin Memory filed for an IPO in October, and some have given the company a valuation as high as $2 billion. Violin Memory manufactures flash memory and high-speed storage systems that are used by companies like Oracle and Cisco Systems. Companies involved in "big data" are popular picks to move into the capital markets -- VCs more than doubled their investments in big data firms this year -- and some Violin competitors, like Fusion-io in 2011, have already made the leap. Violin CEO Don Basile joined the company in 2009 after leaving Fusion-io, where he also served as CEO.

Square

Square's electronic payment app has helped credit card companies infiltrate small merchant businesses. Farmer's markets, food trucks, and hole-in-the-wall bookstores -- locations where credit cards were practically non-existent -- are now able to accommodate customers with plastic. Square has been a staple of the IPO rumor mill since it hired Sarah Friar as CFO in June. Formerly a vice president at Salesforce.com (CRM), Friar also worked for 10 years at Goldman Sachs (GS) and is the kind of experienced CFO companies need to make their way through an IPO. Square's partnership with Starbuck (SBUX)s in August pushed its end-of-year 2013 valuation estimate as high as $5.5 billion.

Xoom

Sources confirmed that Xoom, an online money transfer service that competes with services like Western Union, has indeed filed an IPO. Over 700,000 customers used Xoom to transfer nearly $3 billion in funds during the company's fiscal year, which ended in September. Analysts like the company's management team and predictability. Xoom is led by CEO John Kunze, previously the chief exec at Plumtree Software, which BEA Systems acquired in 2005. Xoom's board boasts a number of experienced financial minds who may be able to offer IPO guidance, including former PayPal CFO Roelof Botha, and Murray Demo, previously CFO of Dolby Laboratories, Inc. Xoom declined to comment on a potential IPO.

Dropbox

Analysts are high on CEO Drew Houston and Dropbox's business model. The company's free storage offering has made it a hit with casual consumers. Dropbox announced it had reached 100 million users in November and estimates place the company's valuation at $4 billion. And Dropbox's rapid growth, strong brand, and knack for innovation have helped build the company's reputation among analysts.

Arista Networks

Some hold that Arista is a bit undersized for an IPO, but the Silicon Valley computer networking company seems poised to file in 2013. In October, Arista hired former Palo Alto Networks CFO Michael Lehman, who left that company "IPO ready," according to Arista's press release. In March, CEO Jayshree Ullal told Reuters that Arista had doubled its revenue every year since launching in 2008. Ullal is respected among analysts and business minds in Silicon Valley, and she spent 15 years as a senior vice president at Cisco (CSCO) before moving to Arista.

Box

Box has been highly visible over the past few years. The company, which offers cloud-based content management and file sharing services, attended the Credit Suisse Annual Technology Conference in late November, a sign that management is at least kicking the tires on an IPO. Merely attending an investment banking conference doesn't guarantee anything (Box was also at a Goldman Sachs conference in 2011), but companies don't show up by accident. Box nearly doubled its workforce in the past year to 650 employees, and it was valued at roughly $1.2 billion following a substantial funding round in July that brought in $125 million. Estimates suggest Box may seek an IPO valuation between $2-3 billion.

Marin Software

CEO Chris Lien hasn't been shy about plans to take Marin Software public in 2013. The San Francisco-based startup offers an online advertising management platform to customers to maximize client ad dollars. Since launching in 2006, Marin has opened 11 offices worldwide and grown to more than 400 employees, but the industry is growing even faster. Online ad spending is predicted to reach more than $100 billion in 2013, and Marin Software hopes to claim a piece of that pie. Revenues at Marin in 2012 will end up close to $58 million. The company has recently gone quiet regarding IPO plans, a sign that the process is underway.

Kabam

Kabam offers hard-core games on mobile, web, and Facebook (FB) to more than 4 million users per month. Kabam's Kingdoms of Camelot brought in more than $100 million in revenue in only three years. The company claims revenue growth of more than 50% for 2012, and should end with over $150 million in revenue for the year. CEO Kevin Chou has experience with both public companies and IPOs. Previously with VC firm Canaan Partners, Chou has also advised public tech companies on mergers and acquisitions and corporate finance for Deutsche Bank (DB).

Opower

Washington, DC-based Opower provides utility companies with cloud-based software aimed at minimizing energy waste. The company is growing quickly, working with data from more than 50 million U.S. homes. Opower expects to reduce American energy costs by $200 million in 2012. The company is not involved in solar energy -- an industry that has generally struggled in the markets -- and instead simply helps consumers cut down on current energy waste. CFO Thomas Kramer was previously with another IPO-ready software company, Cvent, which helps businesses plan and orchestrate conferences.

10 IPOs to look for in 2013