Unlike National Poetry Month, National Poetry Writing Month ("NaPoWriMo") is not a celebration officially recognized by any state or US governmental office. Instead, it's a challenge to those who want to write poetry: finish 30 poems in 30 days.
NaPoWriMo was unofficially "started" by poet Maureen Thorson, of Washington, DC, back in 2003. She wrote 30 poems over the 30 days of April, and posted them on her blog. When other people wrote poems, she'd link to them. After a few years, the community grew so large that Thorson decided to create a website just for NaPoWriMo. You can go there and click on the Participants' sites link to read poems by people participating this year, or submit your site if you want to accept the challenge and publish your poems for others to see.
NaPoWriMo is not affiliated with National Novel Writing Month (NaNoWriMo) or National Script Writing Month, but it is still a non-profit endeavor.
The above photo was taken by Steve McLauglin and found here, through Flickr. The photo is protected by a Creative Commons copyright.