As I was preparing this, Emily Short made a massive post which seemed to cover every text game event ever.
This is just 2015, roughly in chronological order. If you want more detail, a lot of the events mentioned here are mentioned there as well, complete with organizer commentary.
While this list has mostly competitions, it’s not intended to be exclusively about them. Anyone who intends a Kickstarter, conference, public reading, etc. is welcome to let me know and I can add it to the list.
2015 Concours d’aventures textuelles
This competition for interactive fiction in French goes from January to February.
ParserComp
ParserComp 2015 is a ranked, long-form game jam for parser games (also sometimes called text adventures).
Writing window: November 1, 2014 through February 1, 2015
Polish window: February 1, 2015 through February 14, 2015
Voting window: February 16, 2015 through March 14, 2015
Imagine a World
February will see the Kickstarter launch by Adri of
a multimedia text adventure called “Imagine a World.” It’s a prequel to the world of Glitch, an MMO by Tiny Speck that shut down a few years ago.
Shufflecomp II
The sequel to Shufflecomp will be announced in Feburary.
The original premise was
You sign up by sending me a list of eight songs that you think might make for good games. I shuffle them up, and send each participant eight songs. They pick one and make a game vaguely inspired by it.
(The image above is from songs used last year. From left to right: White Houses, Smooth Criminal, and Chrome Country.)
The Independent Games Festival
I might not normally include this is a “text game event”, but there are a large number of text games in contention for the IGF Awards, including the majority of the “Excellence in Narrative” category.
The IGF Awards take place on the evening of the third day of Game Developers Conference, and are a major celebration of the best in indie gaming, with thousands watching the award presentation before the Game Developer’s Choice Awards are presented. The 2014 IGF Awards, including custom interstitials from Mega64 and Hey Ash Whatcha Playin’?, are available for online viewing. The Festival Awards will take place March 4, 2015.
IF Grand Prix 2015 interactive fiction competition for (mostly) German language games
This competition of is for short works (90 minutes or less). Both parser and choice interface works are allowed.
March 1, 2015 12 p.m. CET: Deadline for submission of intents.
April 1, 2015 7 p.m. CET: Deadline for entries.
April 1, 2015 12 p.m. CET: Entries will be released to the public.
May 1, 2015 11.45 p.m. CET: Voting deadline.
May 2, 2015: Results will be published.
2015 Spring Thing
Formerly a “competition” for interactive fiction, the rebranding as a “festival” indicates a new focus on showcasing and promoting new games in a friendly, less competitive environment.
March 1, 2015: Deadline for authors’ intents to enter.
April 1, 2015: Deadline for games to be submitted.
April 4, 2015: Festival opens.
May 4, 2015: Festival closes; ribbons awarded and games archived.
Windhammer Prize for Short Gamebook Fiction
It is the intention of the Windhammer Prize to promote the gamebook genre, and in doing so deliver to readers new and original adventures that express the innovation and creativity that can be found in authors of interactive gamebook fiction today. In pursuit of this objective the Windhammer Prize values most those gamebook entries that expand the boundaries of the genre. If you believe you have an idea for a work of interactive fiction that is both original and innovative then this competition is definitely for you.
Entries are accepted from August to the beginning of September; voting closes the end of October.
This competition includes a unique incentive:
The publication of winning entries is a commercial opportunity being offered by Tin Man Games that is available to First Prize and Merit Award winners. Publication will be offered as an idevice app that includes these three winners within the one 2014 compilation title.
2015 IFComp
The Interactive Fiction Competition is an annual event begun by passionate hobbyists in 1995 to encourage both the creation and the discussion of new interactive fiction works (also known as IF). While the definition of IF has evolved in the years since then, the IFComp’s format and schedule have remained stable since the 1990s. Anyone can judge the entries on a one-to-ten scale, and the laurels go to the entries receiving the best average rating.
Deadline for entries is near the end of September, while judging lasts until November.
Wordplay
WordPlay is our free festival celebrating the most interesting uses of writing and words in contemporary games. Each year there will be a curated game showcase, talks by creators about the craft, and ways for the public to learn about making games.
The festival occurs early November in Toronto.
CRIL
This competition for Russian interactive fiction goes from November to December.
Renga in Blue 
Also look out for ShuffleComp II, now under the stewardship of Neil Butters; Neil just announced on intfiction that this year’s official announcement should be around Feb. 15, with much the same timing as last year’s comp.