When Vincent Guerin arrived to be the new director of the Institut francaise d'Ecosse in Edinburgh, a venue that had once been a compulsory Fringe visit was entirely off the map.

That he is leaving after his designated five year term of office with the Randolph Crescent premises a vibrant centre of Francophile performance once again speaks of a man whose dynamism is rather belied by his relaxed, laid-back demeanour. Typically, when we chat over that time in the institute's library in the minutes before the 2015 programme is launched in the theatre space upstairs, it is I who look at my watch, worrying that I may be keeping Guerin from his assembling guests.

I put this unflappability down to having promoted music at home in France before coming to Edinburgh, a milieu in which always appearing chilled is not just sensible but de rigeur. That it comes with a generosity with his own time, and a willingness to share the whole building with the companies who not only set out their stall on the Fringe but also live on the premises during their run.

When Guerin talks about "curating a venue for the Fringe", he indicates a selection process for the Vive Le Fringe! programme that embraces people he judges will benefit from the experience.

"After all, we hae to live with them for a month," he notes with a smile.

"The Fringe is a great opportunity to engage with the international audience, but I need the companies to think deeply about how they will work here. Some I may have seen at the Avignon Fringe but they can only have the opportunity here when they are ready. They need to have passion and commitment."

In some cases Guerin has invited the companies to Edinburgh the year before they will perform, so they can grasp the enormity of the beast (Avignon's "Off" is bijou by comparison). This acclimatisation has involved the director sending his guests out into Fringe-land with the instruction that he does not expect to see them again for 10 days. After that, he reckons, they will appreciate what is involved in bringing a show to Scotland in August.

"If you have a story to tell, you can get an audience. You are not going to make a fortune, but you will learn and make contacts and gain important feedback on your own artistic work. You can - and shoudl - engage with the audience in the cafe bar here and when you meet them elsewhere in the city."

Understandably, this evangelistic attitude towards the Fringe experience has been seized upon by Festivals Edinburgh and Fringe Central, and Guerin has been ambassador for Scotland in France and elsewhere as much as he has been for France in Scotland.

The artistic cross-fertilisation he has fostered has meant French-speaking companies creating new English versions of their shows as well as picking scripts in Edinburgh to make French versions of back home. This year's programme includes a return by director Matthieu Roy, working with a new translation by former Traverse literary manager Katherine Mendelsohn of a play by Gustave Akakpo, now entitled Skins and Hoods, which won praise for its combination of film and live action in Avignon.

While that plays indoors, there is a full programme in a tent pitched in the gardens across the road in Randolph Crescent, much of it wordless and aimed at a family audience. The marquee is a successor to the tent a company brought last year, and the expansion outside the building another Guerin innovation.

Which poses the question of what happens when he departs from the director's post, with dramatic suddenness just two hours after the last Fringe show ends on Monday August 31. In fact he is not being replaced, the French having decided to give responsibility for the direction of the Institut francais d'Edinbourg to the incoming consul general. The good new is that Vive Le Fringe! will live on, as a separately-constituted not-for-profit organisation with connections to the Institut francais in both Edinburgh and London, and directly to Paris and elsewhere in France.

Guerin and his wife and young family are happily settled in the Scottish capital and he intends to undertake other projects to keep food on the table, but the transformation he has brought about in Randolph Crescent looks set to continue.

This Frenchman's Fringe philosophy is simple: "We had a theatre, so we had to be part of the craziness."

The Vive Le Fringe programme runs from August 7 to 31. www.vivelefringe.org