A couple years ago, Austin Mayor Steve Adler said he wants Austin to be the social innovations capital of the world. And before and after that proclamation, Austin startups, nonprofits and investors have taken huge steps toward making Austin a hub for social impact entrepreneurship.

Tarmac TX is of the organizations having a big impact in fostering that growth. The incubator, which is backed by San Francisco-based nonprofit CALSO and 3M, is focused on fostering tech solutions that address social and environmental issues in Austin. The program provides mentors, networking, product testing and other assistance to social entrepreneurs to help bring their solutions to market or improve their existing products. And many of the startups that have gone through the program in previous years have gone on to do pretty cool things.

So, with that in mind, let’s check out the Austin startups going into Tarmac TX’s free, nine-month incubator program.

Please note: The company descriptions below come directly from Tarmac TX.

AquaSprouts

By combining fishkeeping and hydroponic gardening thanks to aquaponics, Aquasprouts succeeds in reducing dramatically waste and maintenance of your aquarium and your plants. By circulating the water from your aquarium through the Garden’s bed, the AquaSprouts Garden recycles fish waste to provide vital nutrients for growing plants, leaving the water clean and clear without the need for additional filters or frequent water changes.

Care2Rock

Care2Rock offers one-on-one online music lessons via live video with superior teachers who are changing the world. In addition to teaching paid lessons on the site, instructors volunteer to teach one child in foster care for free for a one year period. If a teacher is unable to volunteer, Care2Rock donates $2 per lesson to nonprofit organizations supporting children in foster care. Care2Rock seeks to achieve measurable social impact by utilizing income-producing online teachers as long-term volunteers for youth in foster care.

CoachTube

CoachTube provides access to online training from the world’s best coaches. CoachTube empowers coaches to create courses online to give every athlete in the world access to the instruction, knowledge, and the motivation they need to grow and progress as athletes and students. CoachTube already has over one million visitors a year. At TarmacTX, CoachTube will leverage these great achievements to promote Sport for All.

GrubTubs

GrubTubs is a Table to Farm Food Waste Recycling Service. By using tech, they help restaurants recycle their leftovers. GrubTubs provides restaurants with Tubs for leftovers, which they collect and deliver to local grub farms. Once fully grown, Farmers harvest the grubs and feed them to chickens. Chickens love eating grubs, it’s the staple food of their natural diet and a fantastic recipe for healthy eggs. GrubTubs makes it easy for restaurants to give back to those farmers who keep feed local and affordable.

JoeVolunteer

JoeVolunteer is creating an app to connect any volunteer around the world with worthwhile organizations that need their help. JoeVolunteer aims to make it “crazy-easy” for anyone anywhere at any time to be a volunteer, even if it’s just for less than one hour. Wherever you are — and whether you have less than an hour or more than a week to help an organization in need — you just open your phone, and it will list the opportunities available to you to be someone’s hero.

ShowerStream

ShowerStream invented a shower device that produces 20% water saving in hotels. The device focuses on eliminating the wasted shower water during the time that the water warms up. With a device as easy to plug in as a light bulb, ShowerStream keeps the water at the right temperature at all time. ShowerStream is the end of the era of waiting for your shower water to warm up.

Think and Zoom

Think and Zoom is an innovative technology solution for the visually impaired, that is over 285 million people worldwide including 10+ million Americans. Think and Zoom uses the Google Glass technology to create a hands free visual magnification powered by the human mind. Wearing Google Glass and EEG headset, you can zoom in on objects and see better by simply thinking.

Trashbots

Trashbots develops low-cost science and engineering kits with an artistic twist and a structured curriculum that enables young people to develop problem-solving skills and enhance their creativity. These STEM kits allow you to build robots that utilize found materials in the world around you. TrashBots is a solution that has mass appeal on a global basis and can meet the needs and budgets of underprovided kids in developing countries.

YanEngines

From chainsaws to container ships – YAN Engines is developing the D-Cycle piston, which can be retrofit or designed into existing internal combustion engines, resulting in a 20% increase in fuel economy without sacrificing performance. YAN Engines is working on prototypes for both gasoline engine and diesel engines, but its technology can be integrated into nearly any engine currently used.