George Kinnear and Steven O'Hagan first conceived the idea of offering a free Higher Still notes online service in May 2003 when they were fifth-year pupils at West Calder High. By September of that year they had bought the domain name hsn.uk.net and during their sixth year they developed content, features and provided an online forum for pupils and teachers to exchange information.
Now they have set up a business selling teachers homework exercises, practice NAB assessments and exercises designed for teachers by other teachers. Money from the online subscription service allows them to continue offering the revision notes free to pupils.
Last year, the website received more than 1,000 visits on the eve of the Higher English exam and 17,500 altogether during the month of May when it offered revision notes on six subjects. There have been around 50,000 downloads of all the notes on the site this year, 20,000 of these being for Higher maths alone.
The list has been extended to cover nine subjects - Higher chemistry, maths, information systems, business management, computing, economics, English, and physics, and Advanced Higher computing - and the site received 7,000 visits this month.
"Maths is definitely the most popular," George Kinnear said.
Both he and Steven O'Hagan are studying maths at Edinburgh University and the experience of engaging with pupils and teachers through the website has encouraged them both to consider teaching when they graduate.
Their site has been named "website of the month" by Learning and Teaching Scotland, and the BBC's bitesize revision site provides a link to it.
Initially, it provided versions of the revision notes in maths and chemistry that they had been given by their class teachers. As both received five A Higher passes and As in Advanced Higher maths, it's a fair assumption that they were being well taught.
Over time other teachers have become involved in checking the accuracy of the notes.
"The main thing is that pupils are helping other pupils through the forum.
They are able to post a question and minutes later get an answer," Mr Kinnear said.
"With our own studies at university we have found that we have become a lot more focused on being very accurate with the maths so we are rewriting the maths notes, extending them and making them more detailed.
They have had particular guidance from a teacher with experience as an examiner in maths and held a workshop earlier this year at the Scottish Mathematical Council conference.
In subject areas outside their particular expertise, such as English and economics, they rely on other students to contribute and then ask teachers to check the notes for accuracy.
They don't make money from the venture and spend 10 to 15 hours a week refining and managing the website. So why do it? "It all just started off as a little project but we have been very encouraged by the feedback. It's a positive thing and it's really nice to receive feedback from people who have benefited from what we have been doing," Mr Kinnear said.