Georgia Cyber Academy, a massive online charter school, started small, tapping a market of home-school parents who wanted the support of a formal school curriculum.

Marty White, of Lawrenceville, enrolled four children there, realizing that she could expose them to public school resources while keeping them immersed in her “Christian perspective.” One of her children, Valerie, 12, liked what a public school had to offer, too. “I like that I have real teachers besides my mother,” she said.

There are now several full-time “virtual” charter schools serving Georgia students, but the academy, with its head start, is about three times larger than its nearest competitor.

On its path to growth — it now enrolls more than 13,000 — it took on an increasing variety of students. The extraordinary diversity was on display at the commencement in May, held in a brimming hall of the Cobb Galleria. Black families from urban Atlanta sat next to white families from farming communities. Women with head scarves walked past men in camouflage coveralls.

Many came for the same reasons: they didn’t like what their local schools had to offer. One father from south Georgia said he enrolled his son in the academy after paying to send him to a nearby county school district. His own county system was “terrible,” he said, and there was no way he’d have sent him there.

Along with the growth has come students who lack the support of a full-time parent-teacher. Perhaps that’s one reason the future of the school is cloudy. Performance is near the bottom in Georgia, despite the tens of millions spent each year by taxpayers.

In a report on Sunday, The Atlanta Journal-Constitution explores the promise, and reality, of a high-tech education at the academy.

In the meantime, here are some of the better-known programs in Georgia …

Enrollment in fall 2015: 13,916

Grade from Governor’s Office of Student Achievement: D

Description: A charter school authorized by the State Charter Schools Commission, serving students from kindergarten through high school with “a combination of self-paced work and scheduled lessons and activities” and a program that lets students “individualize their education, maximizing their ability to succeed.”

Enrollment in fall 2015: 3,866

Grade from Governor’s Office of Student Achievement: D

Description: A charter school authorized by the State Charter Schools Commission, serving students from kindergarten through high school “for whom a cutting-edge online education provides the best pathway to school success.”

Enrollment in fall 2015: 1,864

Grade from Governor’s Office of Student Achievement: F

Description: A charter school authorized by the State Charter Schools Commission, serving “historically underserved” high school students with “a flexible and highly individualized” online experience.

Enrollment in fall 2015: not reported*

Grade from Governor's Office of Student Achievement: not reported*

Description: A part-time school operated by the Georgia Department of Education to offer middle and high school level online courses for students enrolled at other schools, with over 100 offerings in core content areas and a “vast” Advanced Placement course selection. “Your student’s options and opportunities are not limited by the school district in which you live or the school they attend.”

*State agencies do not record the performance, enrollment or other numbers of part-time schools.

Enrollment in fall 2015: 464

Grade from Governor’s Office of Student Achievement: C

Description: A county-run school for Gwinnett County students from fourth grade through high school. Students through ninth grade get a “blended” experience, part online and part in “learning labs” at a physical campus. Older high school students are on campus one afternoon per week to meet teachers face-to-face but otherwise study online.

Enrollment in fall 2015: 96

Grade from Governor’s Office of Student Achievement: C

Description: A county-run school for Forsyth County students in sixth grade through high school who want an online alternative to traditional school, with a flexible schedule, especially homeschooled or private school students “seeking an academically rigorous” and accredited education.