Have some questions

1) does gretl has a online version on a website? R has online version

2) does the ensure uniform sample size on the view-->corr implies using the least number of sample observations? A variable has 20 sample observations and B veriable has 26 observations choosing ensure uniform sample size implies gretl would use the first 20 observation from both variable? what about there are missing observations in between variable B what would gretl use?