They have to generate income in order to operate, but profit is not their main concern.
They range across a spectrum - from ordinary businesses that donate all their profits to charity to businesses set up primarily to help people, such as Trade Aid.
Being a social enterprise can help sales, one of the organisers, Marianne Archibald, says. "As a consumer I want to buy products from places that have a social conscience."
The other two collaborators are Horizons regional councillor and Green Party member Nicola Patrick and Andre Taylor, chief executive of Maori health and development organisation Nga Tai o Te Awa.
There are plenty of social enterprises in the region already, Ms Patrick pointed out.
They include The Citadel, a cafe in Castlecliff that aims to provide jobs and lift the suburb's standing.
Another example is Pakohe Papers, Marilyn Vreede's business making harakeke (flax) paper and Maori educational material.
"This expo is our first big splash into the community," Ms Patrick says. "We have amazing speakers coming who have achieved results already. We know they will be inspiring.
"Social enterprise is the idea of business that has positive social, environmental and cultural impacts.
"We want to help people follow their passion, make a difference and make a living, but sometimes just taking that first step is hard - especially if you're not confident about where to start.
"We're here to help and have access to some very experienced mentors."
Day One of the event is at the War Memorial Centre and has a key note speaker, Julia Milne of Common Unity Project Aotearoa in the Hutt Valley, then three panels:
•!Rural enterprise: Dan Steele (Blue Duck Station), Warren Furner (Ruapehu District Council), Melita Farley (Double Farley and Confluence), Panapa Ehau (Hikurangi Enterprises)
•!Arts and innovation: Taaniko Nordstrom (Soldiers Rd Portraits), Kendal Collins (Sisters United), Ash Patea (Whanganui River Tours), Marilyn Vreede (Pakohe Papers)
•!Health and hospitality: Levi Armstrong (Patu NZ), Sonia Tiatia (DINE Academy), Charlotte Melser (The Citadel Cafe), Jess Ducey (PledgeMe)
Day two is at Nga Tai o Te Awa and will have coaching and mentoring for people wanting to get started, plus tours of local social enterprises. Among the mentors are:
•!Sharon Bryant - an experienced impact investor in digital. •!Andrew Tripe - a strategy person with broad experience across global organisations in HR and culture change.
•!Taaniko Nordstrom - more than portraiture, she has insights into cultural identity and marketing.
•!Andre Taylor - startup expert and serial entrepreneur who asks the hard questions.
•!Sera Lilly - a social media expert and entrepreneur helping people make positive health
changes, who has a passion for supporting teen mums.
•!Julia Milne - key note speaker from Day 1 who will leave the audience inspired and asking how to replicate her grassroots community development, creating sustainable local jobs.
•!Chris O'Neill - the Akina crew member with a speciality in the arts sector and governance.
•!Cindy Hoskin - a local BNZ business partner.
Many activities are free on Day Two but bookings are essential (via www.eventbrite.co.nz). Tickets for Day One start at $20 for secondary school students.
Following the launch, Thrive Whanganui plans a series of programmes in 2018, including workshops, a start-up weekend and a four-month incubator programme.
Find out more at: www.thrivenow.org.nz or follow on Facebook: @ThriveWhanganui, or drop into 142 Guyton Street, Whanganui, phone 06 348 9902.