Indiegogo is without a doubt Kickstarter's biggest competitor right now. The crowdfunding service raised a $15 million round of funding earlier this year and used it to expand into several new markets abroad, including Canada, the U.K., France and Germany. Indiegogo bills itself as "the largest global crowdfunding platform" which putspressure on Kickstarter to build up its own international presence.

Both Kickstarter and Indiegogo ask aspiring entrepreneurs to set fundraising goals and offer rewards in exchange for various funding amounts. A big difference between the two, however, is that Indiegogo offers startups the option to collect the money even if they don't hit their fundraising goal. In these cases, Indiegogo takes a bigger cut of the money transferred.

Peoplefund.it recently partnered with Crowdfunder to create a powerhouse for crowdfunding in the U.K. -- posing a challenge to Kickstarter's entry into that country. Peoplefund.it now reaches more than 2 million users in the U.K. The site started out as a way for charities to raise money and has since turned into a platform for British entrepreneurs, which functions just like Kickstarter.

Smallknot takes a slightly different approach to crowdfunding than Kickstarter. Launched this summer, Smallknot serves as a platform for users to invest in small business in their community. It functions the same way as Kickstarter -- relying on an all-or-nothing funding model -- but the goal is to help build a relationship between users and their local businesses.

RocketHub functions very similarly to Kickstarter and supports a wide range of projects from musicians, entrepreneurs and philanthropists.

Gambitious has tweaked the Kickstarter model slightly and applied it specifically to video games. For starters, rather than allow anyone to launching a crowdfunding campaign on the site, the staff at Gambitious actually meets with the game creators to vet their business plan. Beyond that, Gambitious ditches the rewards model and instead offers donors a share of the game's profits if it's successful.

Medstartr is taking the Kickstarter idea and applying it to an area that had previously been overlooked by the crowdfunding wave: health care. The site serves as a platform to pitch and raise money for medical tech. It has successfully funded projects ranging from an app that helps patients with diabetes to a special bra to help women who have undergone reconstructive surgery. it may just help speed up the pace of innovation in the medical industry.

Spot.us is essentially a Kickstarter for community journalism. The service, which was acquired last year by American Public Media, gives reporters and news publications a new way to solicit money from readers to fund the story.

Some musicians -- most notably, Amanda Palmer -- have found success funding their albums through Kickstarter, but GigFunder wants to help these artists solve a different problem. GigFunder lets fans launch crowdfunding campaigns to pay for their favorite small bands to go on tour in their hometown.