Thanks, Staci and thank you all for joining us today. In the third quarter of 2018, Appian's subscription revenue grew 42% year-over-year to $29.4 million. Our non-GAAP loss from operations was $8.1 million. Our subscription revenue retention remained high at 117%. These results exceeded our guidance. This quarter, we sponsored a survey of tech executives asking about their IT investments. These execs reported that the role of software in the enterprise is changing. They used to be about efficiency gain and cost reduction. Now it's about the customer, capturing more customers or improving customer service, sounds right to me. This has implications for the pace of software development. Back office apps can roll out slowly, but front office apps have to keep up with the customer, the customer changes quickly. Low-code is a good way to make apps quickly. So the trend favors us. Further, customer-facing applications tend to be important. They need to be scalable and reliable and performant. Appian's brand of low-code is designed to build industrial strength applications, we call this enterprise low-code to differentiate us from the firms whose low-code is merely a quick start to custom development. One of our customers, the Options Clearing Corporation is the world's largest equity derivatives clearing organization. It's a SIFMU, which is to say it's regulated by the government as a Systemically Important Financial Market Utility. They need to be sure they never fail, but they still need to move quickly. They started with Appian and completed nine critical risk management applications in 18 months. They built their first application in about six weeks and now they are at the point where they can build an application in a single day. Speed and reliability, that's what Appian brings to the low-code market. About a year ago, one of the world's 10 largest healthcare companies became an Appian customer. They built a series of applications to support pre-authorization for medical procedures such as sleep studies, genetic studies, oncology. Because our platform allows them to build applications faster than they had before, they increased their Appian investment in Q3 with a seven-figure deal to support more specialty areas. I'm sure you've heard about our work with Dallas-Fort Worth Airport, they are the fourth busiest airport on earth and an Appian customer for five years, they have several dozen applications already in production covering airportwide operations and still, this quarter, they made an additional seven-figure purchase to improve customer experience and ensure controlled access to secured areas of the airport. DFW demonstrates that even in our best accounts, there is still upside potential. IT executives say that 40% of their organizations time is lost to technical debt. That's another finding from our recent survey. 40% is a staggering piece of the IT economy and this matters to us because Appian applications are largely exempt from technical debt. They upgrade automatically, they acquire new features automatically, they automatically run anywhere even on devices that weren't invented when the app was designed. We're the antidote to technical debt and unique applications. So that 40% number is a good indicator of opportunity for us. We believe Appian to be the most accessible product in our market. That means it takes less work to build an application on Appian than it does on rival platforms and it takes less time to learn Appian than to learn our competitors. To emphasize this edge, we launched a new program this past quarter called The Appian Guarantee. We promise -- in this guarantee, we promise that a customer's first Appian project will be completed in just eight weeks for only $150,000 given a few reasonable restrictions. Our partner, KPMG, will deliver the guarantee in North America and Europe. Other partners may soon participate as well. Also, Appian training takes just two weeks, which is to say any developer can become an Appian developer in 10 days. The guarantee substantiates our accessibility advantage, the ease of learning and deployment. We demonstrated this edge in several Q3 deployments and deals. One existing customer, a top 10 insurer in the US had a notably fast deployment in Q3. They provide property and casualty insurance products and services to businesses globally. This year, they needed to modernize their customer payment system because they weren't able to make payments within their SLAs. In six weeks, a team of three people built an application to orchestrate and ensure payments are made accurately and on time. There's another one, a Big Four auditor, an Appian customer since 2013, expanded their licensing with a seven-figure deal in Q3. They needed to build a mission critical application to meet regulatory requirements pertaining to evidence gathering and client communications. Using Appian, they released two applications in 12 weeks serving thousands of audit team members. We won new customers this quarter due to speed of deployment and ease of use. We captured a new global investment and advisory firm with more than $300 billion in assets under management. They needed to track employee trading activity to reduce the risk of insider trading. They'll use Appian to build a know-your-employee monitoring tool for their 2,500 employees. During the evaluation cycle with this customer, a single Appian sales engineer built a compelling custom demo in six days, just six days. We beat two of our biggest competitors due to our speed. One of the UK's five largest banks also became a new customer of Appian in Q3. They faced pressure from regulators to improve the quality of their reporting by the end of the quarter. In just six weeks, three people built an application to allow their finance team to track and report on P&L for their business units. The accessibility of our platform also won us new US federal agencies and led to expansions in existing ones. This quarter, we won a federal agency responsible for environmental conservation. They needed a better way to track constituent requests for environmental impact analysis on marine species. Earlier this year, an agency employee, independently of Appian, obtained an Appian cloud trial, taught himself how to use Appian. The employee built and demoed three applications to senior stakeholders using our cloud trial and these demos, created by an Appian neophyte, made this federal agency a new Appian customer. We also expanded with the U.S. Department of Labor. Before purchasing Appian, they had 39 disparate case management solutions. They replaced five of those systems with their first Appian licenses. This quarter, they more than doubled their user base with a seven-figure deal to modernize another dozen case management systems. We won this deal because DOL finds our accessibility and the security of Appian cloud critical to modernizing their systems. Appian was one of the first companies in the world to meet the US federal government's strict security requirements called FedRAMP. Even today, not all of our competitors have this essential cloud security certification. We continue to emphasize accessibility in The Appian Guarantee, in proofs of concept, and in our pitch because it's a theme we continue to win on. Now I'll turn the call over to Mark for a deeper discussion of our financials. Mark?