Over the next few days, I AM BREATHING will play in 164 screenings (and counting) all over the world.

Thanks to the incredible community of ordinary people, promoters, documentary enthusiasts, distributors, festivals, MND/ALS activists and volunteer translators, it will screen in venues ranging from cinemas in New York, Copenhagen, Moscow to universities in India, a library in Rwanda, a taxi cab in England... and maybe, most important of all, in living rooms of families whose lives have been touched by what Neil called "this bastard of a disease."

Increasingly I think this film is not just about Neil, but about all of this community.

It's about those who will hold their breath before they screen the film, reminded of how this disease may ravage their own bodies, or those who will be remembering the person they love who has died from it. There will be some who watch this with no speech because of this illness, or with no ability to move or breathe – like Neil. Those who live the unimaginable lives of paralysis that most of us can barely dare to think about.

In this film, and in his blog, Neil forced us to think about it not just for himself, but for those who couldn't speak. He wanted to "smack you in the face" he said. He has, and continues to do so after his death through sharing his vulnerability. By showing his weakness, paradoxically Neil gained strength and wanted this for others too. He wanted it for those suffering of MND in particular – but also for others whose lives are touched by suffering.

I think that includes all of us. Aren't we all affected by what Neil called the "when of things"?

We live in strange times in a culture so afraid to show pain and suffering that methods of communication like Facebook are often about showing a facade to the world which is the very opposite of vulnerability. Neil knew this online community could be used to connect in a more honest, rawer way. This is what has happened in a startling way with this film. Every day, we are moved by the posts shared on this website and Facebook which show such courage.

I think the film is not really just about Neil any more, but with the incredible uptake of this Global Screening Day, more than ever, it is about this amazing community of people all over the world – people living with MND/ALS, carers like Lindsey Lonsborough in England whose husband Mark who has been living with MND for 11 years now, or a teenage sufferer of MND in Kenya.

When we screen the film on 21 June it is as an offering of hope, a call to action – and a stand in solidarity for you all. Thank you for your bravery, your generosity – your determination not to be invisible.

Warm reception of our film at this fab Hot Docs festival in Toronto where audiences have multiplied over the years.  Such is this city's passion for documentary that there is now a cinema called The Bloor which shows nothing but documentaries all year – I AM BREATHING will show there on June 21st. Programmed by the tireless Robin Smith, it is a great model  for other cities,  defying all expectations with the steady audiences it attracts. 

Canada is a natural home for documentary. We exported Grierson here who went on to start the National Film Board and now  the tradition is stronger than ever – though funding is under threat. 

Local filmmaker Kevin McMahon  feels documentary should be protected as a "cherished cultural form" in Canada, with the same significance as "the beaver, the colour red and Maple Leaf tartan."  He quotes that great Canadian thinker  Marshall McLuhan who felt that Canadians were inherently good observers because "when you are out of the main swim, as it were, you have a much better opportunity of seeing what's going on."

Morag McKinnon directed I AM BREATHING together with Emma Davie. She had met Neil and Louise while studying at Edinburgh College of Art. 

I didn't know Neil all that well at Art School. Memories are hazy and consist of just general fun, laughter and nights at the pub.

There was a lot of fun and a LOT of laughter - and Neil played his guitar and sang songs. I remember Neil's dad had died and he had dealt with it incredibly well. He had that Yorkshire pragmatism of just getting on with things and most importantly - he kept his sense of humour.

The group of friends that kept in contact since Art School have I think all been held together over time by a shared sense of humour. Neil's idea of ribbing a friend who wasn't able to spend his last new year with him was to send a text with a photograph of him draped in a sheet with a toe tag on. I think it was his way of being undefeated by the disease and utterly remaining himself.

Emma Davie wrote this for the Campfire Stories event at the True/False Film Fest, where filmmakers gather around a 'campfire' to swap tales of the scene that got away.

It was the tape we didn't want to look at.

For weeks it lay in a shoe box under the edit suite. Unseen, unlogged, undigitised.

It was not long after Neil, our friend and main character, had died, and Morag and I had started editing the footage ourselves. It was very raw to see again how he had struggled. We often got upset and wanted to stop but we felt we had work to do. Neil had a Yorkshire no-nonsense approach to his own suffering so we also tried to "man up" as he'd say and get on with it.

We wanted to get a sense of how the film might work, how we could mingle his voice with his written words, if we could rise above the incredible suffering he went through to produce a universal story. We worked silently. Me at the edit suite, Morag beside me.  We had a good understanding of what each other thought so didn't really have to say much about how we worked – or about our attitude to the tape in the shoe box under the table. We just knew we'd carry on avoiding it for as long as possible.

In Helsinki, I AM BREATHING played first in the Andorra cinema – the one founded by the great Finnish directors Mika and Aki Kaurismäki. Some who have seen our film say Neil's humour is Kaurasmäki-like. A welcome Finnish compliment.

After the screenings, audience members offer to show the film on the Global Awareness Day for MND/ALS, even though it will coincide with Midsummer when every Finn goes wild in the country. Others say after the film they went and had a beer “for Neil”.

Sometimes I feel sharing this film with an audience is more of a séance than a screening. In that dark space of the cinema, Neil seems to come to life beyond the film itself. He is almost alarmingly present in a way which surprises me.